We then used the APL leukemic cell line NB4, the myeloblastic and monoblastic cell lines HL60 and PR9 (derivative of U937, with zinc-inducible PML/RARA), and the non-hematopoietic cell line HEK, to characterize the regulation of FOXC1 expression. This evidence concerns the gene RARA and acute promyelocytic leukemia.