MTAP and neoplasm: Deletions of methylthioadenosine phosphorylase (MTAP) are frequent in several malignancies and lead to 5′‐deoxy‐5′‐methylthioadenosine (MTA) accumulation, competing with S‐adenosylmethionine (SAM) for binding to Protein Arginine Methyltransferase 5 (PRMT5) and enhancing tumour sensitivity to PRMT5 inhibitors.1, 2