FADS1 and esophageal squamous cell carcinoma: The mRNA levels of genes associated with unsaturated fatty acid synthesis, including ACLY, ACC1, SCD1, SREBP1, FADS1 and ELOVL5, were significantly greater in ESCC tissues than in adjacent normal tissues (P < 0.01; P < 0.01; P < 0.01; P < 0.01; P < 0.001; P < 0.05) (Fig. 5G–I), suggesting active unsaturated fatty acid synthesis and de novo lipogenesis in tumor tissues.