3.2.2.6 additional information no induction of CD38 mRNA by senescence itself. Cytokines and chemokines expressed by senescent cells induce CD38 expression in macrophages 3.2.2.6 up 0.001 mM ATRA induces CD38 expression 3.2.2.6 up enzyme induction by retinoic acid in HL-60 cells 3.2.2.6 up in cultured macrophages, lipopolysaccharide LPS can upregulate CD38 expression in time- and dose-dependent manner