CD38 and neoplasm: We cultured hHSCs (Lin- CD34+ CD38lo/-) together with CD38+ tumor cell line or CD38+ progenitors (Figs 5E and S6E) and found that inhibition of CD38 enzymatic activity by 78c inhibitor (S6D Fig) led to the cell cycle entrance of hHSCs (Figs 5E and S6E).