HIF1A and neoplasm: In tumor hypoxia microenvironments, HIF-1α promotes fatty acid uptake by inducing fatty acid binding protein and PPARγ, inducing phosphatidic acid phosphatase LIPIN1 production, regulating fatty acid synthesis, and promoting lipid storage by regulating the expression of acylglycerol-3-phosphate acyltransferase 2 (AGPAT2) and LIPIN1. This results in chemotherapy resistance in tumor cells.