RARB and hepatocellular carcinoma: To identify the RAR receptor(s) mediating the activity of ATRA in TNBC cell lines, we exposed HCC-1599, MB-157 and MDA-MB157 cells to AM580 (RARα agonist), UVI2003 (RARβ agonist), BMS961 (RARγ agonist) as well as ATRA for 9 days (Figure 8A).