Description: IC50 Value: N/A All-trans retinoic acid (ATRA) has been widely investigated for treatments of many cancers including prostate cancer. in vitro: ATRA was able to induce the growth arrest and to increase HOXB13 expression in AR?prostate cancer cells. Both EZH2 and DNMT3b participated in the repression of HOXB13 expression through an epigenetic mechanism involving DNA and histone methylation modifications[1]. ATRA could upregulate HOXB13 through decreasing EZH2 and DNMT3b expressions and reducing their interactions with the HOXB13 promoter[1]. in vivo: Earlier studies revealed that treatment of leukemic cells with ATRA resulted in the apoptosis, presumably secondary to the differentiation process. Since ATRA can rectify aberrant cell growth and induce apoptosis, it has been widely investigated in preclinical and clinical trials for the treatment of many cancer types, including early gastric cancer and prostate cancer . In AR? and drug resistant DU145 prostate