The authors found that cellular lactate increased apolipoprotein C2 (APOC2) lactylation at K70 (lactyl-APOC2-K70), which induced free fatty acid (FFA) release into the TME, extracellular lipolysis, and Treg cell accumulation associated with immunotherapy resistance and tumor metastasis [96]. The gene discussed is APOC2; the disease is neoplasm.