Lam Qua, a Chinese artist who painted in the Western style, was hired by American ophthalmologist and missionary Peter Parker to paint Parker's Chinese patients. Most of Lam Qua's paintings depict patients with rather large tumors located in various areas across the body; there are a few that are also of dermatologic interest. This contribution explores Lam Qua's paintings that depict a cutaneous horn, gangrenous necrosis, and an ulcerating tumor.Many factors affect the health and physiology of human skin, with some of them arising from outer space. This contribution explores four celestial influences on the skin (1) the sun's ultraviolet light, which has both beneficial and deleterious dermatologic effects, (2) meteorite injuries, (3) possible lunar effects on the body's health, and (4) cosmic radiation as a risk factor for skin cancer and pregnancy-related complications.  https://www.selleckchem.com/CDK.html  Some of these extraterrestrial influences on skin health have taken on added significance as human beings increasingly spend more time at higher altitudes in aircraft, spaceships, and space stations.Biotinidase deficiency is a rare hereditary metabolic disease. Only a few cases have been reported in China, almost all of which have been in the pediatric population. We report a case of a girl with characteristic skin and hair findings with a negative family history, although her grandparents were consanguineous. The metabolites in the proband's blood and urine increased prominently, and the percentage of biotinase was 1.168%, much lower than normal. Genotyping identified two heterozygous mutations, which were C.1457T>A (p.L486Q) and C.1491dupT (p.L498Ffs*13) in the BTD gene. The diagnosis of biotinidase deficiency was established. No relevant reports about the missense mutation at the mutation site C.1457T>A (p.L486Q) of the BTD gene have been retrieved. Biotin replacement therapy was administered in the dose of 20 mg/d. The dermatitis subsided after 1 month, and the hair color was almost normal after 3 months. This reminds dermatologists to include biotinidase deficiency in their clinical differential when faced with children's intractable dermatitis, yellow hair, and alopecia.Basal cell nevus syndrome, also known as Gorlin syndrome, is a hereditary cancer syndrome associated with multiple basal cell carcinomas, congenital defects, and nondermatologic tumors. This disease is autosomal dominant with variable expressivity and is caused by abnormalities in the sonic hedgehog signaling pathway. Management requires a multidisciplinary approach and should include the biopsychosocial needs of patients and their families. Genetic testing is necessary to confirm an unclear diagnosis, evaluate at-risk relatives, and assist with family planning.The human genome project yielded a compendium of genetic material that has allowed rapid advancement both in the technique of whole exome sequencing and also in the ability to identify single gene defects. The next generation of genetics has investigated how these genes interact in the development of disease, identifying pathways of illness and end organ tissue abnormal development. From the knowledge of single genes and pathways of genodermatosis development arises the opportunity to produce genetic therapies. This contribution reviews some of the exciting, emerging genetic therapies in genodermatoses.RASopathies are a group of disorders characterized by mutations in the RAS-MAPK pathway. RAS-MAP signaling plays a critical role in cell differentiation, proliferation, and survival. Germline mutations can result in distinctive syndromes, including Noonan syndrome, Costello syndrome, and neurofibromatosis type 1. Mosaic RASopathies can present as localized cutaneous lesions like epidermal nevi and nevus sebaceous, or more extensive conditions such as encephalocraniocutaneous lipomatosis. We review the heterogenous presentation of RAS mutations, discuss new targeted therapies, and highlight areas of uncertainty, including carcinogenesis risk and appropriate screening.The hereditary nature of some forms of cancer was recognized long ago. Over time, recognition of associated findings led to the delineation of numerous hereditary cancer syndromes. Many of these syndromes also have cutaneous manifestations, the recognition of which can lead to their early identification. Recognition of these syndromes allows vigilant surveillance and preemptive treatment, which can dramatically impact the risks of morbidity and mortality for affected patients. The rise of rapid and accurate genetic testing now allows the early identification of asymptomatic at risk family members so that monitoring can be initiated as early as possible. The dermatologist plays a critical role in early identification of these syndromes and, in many cases, their treatment. This review summarizes many known hereditary cancer syndromes with cutaneous findings, their etiology, identification, evaluation, and management. Importantly, this is an ever evolving topic and new findings and syndromes will continue to be recognized. The dermatologist must be always alert to ensure they are detected.Café au lait spots are common birthmarks seen sporadically and in association with several genetic syndromes. Dermatologists are often asked to evaluate these birthmarks both by other physicians and by parents. In some cases, it is challenging to know when and how to pursue further evaluation. Diagnostic challenges may come in the form of the appearance of the individual lesions, areas and patterns of cutaneous involvement, and associated features (or lack thereof). In this review, we aim to clarify when and how to evaluate the child with multiple or patterned café au lait spots and to explain some emerging concepts in our understanding of the genetics of these lesions.Genodermatoses are inherited disorders presenting with cutaneous manifestations with or without the involvement of other systems. The majority of these disorders, particularly in cases that present with a cutaneous patterning, may be explained in the context of genetic mosaicism. Despite the barriers to the genetic analysis of mosaic disorders, next-generation sequencing has led to a substantial progress in understanding their pathogenesis, which has significant implications for the clinical management and genetic counseling. Advances in paired and deep sequencing technologies in particular have made the study of mosaic disorders more feasible. In this review, we provide an overview of genetic mosaicism as well as mosaic cutaneous disorders and the techniques required to study them.