https://www.selleckchem.com/Akt.html In this issue of Cell Stem Cell, An et al. (2020) provide a model to study human X chromosome inactivation. They followed X chromosome activity and traced cellular heterogeneity in naive hESCS, showed that it is caused by incomplete blockade of FGF-signaling, and in doing so isolated cells resembling pre-implantation epiblasts.Large skin wounds in adult mice can heal by regenerating new hair follicles and adipocytes in their center. In this issue of Cell Stem Cell, Abbasi et al. (2020) report how typically scar-forming wound fibroblasts enter a transcriptionally distinct single-cell state of competence during regeneration of new hair follicle mesenchyme.mESCs can self-renew indefinitely in vitro. However, depending on culture conditions some strains are more unstable than others. In this issue of Cell Stem Cell, Skelly et al. (2020) and Ortmann et al. (2020) shed light into the role genetic variation plays in control of ground state pluripotency.Microfabricated and microfluidic devices enable standardized handling, precise spatiotemporal manipulation of cells and liquids, and recapitulation of cellular environments, tissues, and organ-level biology. We asked researchers how these devices can make in vitro experiments more physiologically relevant.Metabolic-associated fatty liver disease (MAFLD) represents a spectrum of disease states ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). Hepatic macrophages, specifically Kupffer cells (KCs), are suggested to play important roles in the pathogenesis of MAFLD through their activation, although the exact roles played by these cells remain unclear. Here, we demonstrated that KCs were reduced in MAFLD being replaced by macrophages originating from the bone marrow. Recruited macrophages existed in two subsets with distinct activation states, either closely resembling homeostatic KCs or lipid-associated macrophages (LAMs) from obese adipose tissue. Hepatic LAMs expressed