,21,22 An explanation of the vulnerability is that the catalytic activity of protein arginine methyltransferase 5 (PRMT5) is sensitive to MAT2A inhibition in MTAP-deleted cells,14 though some studies have demonstrated that the accumulated MTA in MTAP-deleted cells is not significantly detected in vivo23 and the sensitivity of MAT2A or PRMT5 inhibition might be specific in different tumor cells.15 The gene discussed is MTAP; the disease is neoplasm.