S100A3 and myeloid leukemia: As the results obtained in S100A3-silenced HL-60 and NB4 cells exposed to ATRA are substantially similar, our data indicate that the cellular context rather than PML-RARα expression is the major determinant of the different effects exerted by S100A3 on RARα functional activity in myeloid leukemia relative to breast cancer and lung cancer cells.