MTAP and hepatocellular carcinoma: MTA administration to increase cellular MTA levels results in the upregulation of matrix metalloproteinases and growth factors in melanoma cells, hepatocellular carcinoma cells, and fibroblasts.25,42 Moreover, accumulated MTA was found to repress T-cell proliferation, activation, and differentiation.43 Despite these observations, future studies on the targeting of the MTAP/MTA axis must prioritize investigating the mechanisms underlying MTA regulation in neoplastic disease and its role in the context of MTAP deficiency.