We tested the effects of GSK-J4 on the growth of our panel of cancer cells and found that the drug was more toxic in the SMARCA4def cells, with a five-fold lower EC50 than in the MYCamp cells or in the lung cancer cells that are wild type for both SMARCA4 and MYC (Fig. 4a, b; Supplementary Fig. 8a). Here, MYC is linked to lung cancer.