c-Maf induces the expression of maturation markers in HL-60 cell lines. (A) Fluorescence-activated cell sorting (FACS) analysis of the expression of the CD14 and CD11b myeloid maturation markers on untreated HL-60 cells, HL-60 cells treated with TPA for 24 hours, and 4 individual c-Maf expressing HL-60 clones treated with zinc for 24 hours. Negative control antibody binding is indicated by dashed lines. (B) Expression of c-Maf mRNA (top panel), CSF-1 receptor (CSF-1R, center panel), or control G3PDH (lower panel), as determined by Northern blot analysis of total RNA from uninduced (−, lane 1) or zinc-induced (+) control vector-containing (CB6, lane 2), c-Maf–containing (lanes 1, 3, and 4) stable HL-60 clones; or TPA-treated HL-60 parental cells (lane 5). A single blot was initially probed with the c-Maf–specific cDNA probe, stripped, and reprobed with CSF-1R and G3PDH; G3PDH served as a control for RNA loading and integrity.