To identify the RAR isoform(s) underlying the anti-proliferative action of the retinoid, initially, we evaluated the constitutive expression of RARα, RARβ, RARγ, RXRα, RXRβ and RXRγ mRNAs in our gastric-cancer cell-lines (Fig. 2A). The gene discussed is RARA; the disease is gastric cancer.