RA induces the degradation of PML-RAR, PLZF-RAR, and NPM-RAR. (A) Western blot analysis of progenitors cultured in methylcellulose for 8 days in the absence or presence of RA (1 μmol/L) after transduction with RAR (15 μg of protein per lane), PML-RAR (30 μg of protein per lane), PLZF-RAR (40 μg of protein per lane), or NPM-RAR (20 μg of protein per lane). (B) Western blot analysis of cell lines established with RAR or RAR-fusion gene treated or not treated with RA (1 μmol/L) for 40 hours (20 μg of protein per lane). The transduced proteins are designated by the white arrows.