RARA and lung cancer: Unexpectedly, syngeneic 344SQ lung cancer cells, which are relatively resistant to anti-PDL-1 therapy20, and which were subcutaneously injected into 129sv mice before treatment with the RARα antagonist IRX6696 alone, or combined with anti-PD-L1 antibody, did not statistically-significantly affect tumor growth (Fig. 2h).