To help identify the nuclear receptor responsible for ATRA’s effect, BCR-ABL ALL cells were treated with pan-agonists for the retinoic acid receptors (RARs) and retinoid X receptors (RXRs), or RARα, RARβ or RARγ or RXRα specific agonists (Table 1) and the number of viable cells determined by MTT and MTS assays. Here, RARA is linked to acute lymphoblastic leukemia.