RA triggers the myeloid maturation of progenitors transformed by RAR, PML-RAR, PLZF-RAR, or NPM-RAR. Analysis of the expression of Mac-1 (horizontal axis) and Gr-1 (vertical axis) by flow cytometry in cells harvested after 7 days of methylcellulose culture in the absence of exogenous RA (left column) or in the presence of 1 nmol/L RA (middle column) or 100 nmol/L RA (right column). These are the results of a representative analysis; similar findings were obtained in three independent transductions experiments.