CD14 and acute promyelocytic leukemia: Furthermore, in vitro assays performed in NB4 cells corroborate our in vivo results showing that EGCG treatment (12.5–20.0 μl), similarly to all-trans retinoic acid (ATRA; the drug approved for APL therapy), increased the expression of neutrophil differentiation markers such as CD11b, CD14, CD15 and CD66 in NB4 cells in a dose-dependent manner after 96 hours incubation (Fig. 3F).