Tamoxifen-mediated SMARCD3 loss in tumor cells leads to a threefold decrease in the total free fatty acid content, which includes the monounsaturated fatty acid oleic acid, the polyunsaturated fatty acid docosahexaenoic acid, and the long-chain saturated fatty acid tridecanoic acid; these fatty acids are involved in the synthesis of complex lipids and play roles in cancer cell signaling and survival. The gene discussed is SMARCD3; the disease is neoplasm.