A signature of five metabolic genes indicative of dedifferentiation and poor clinical outcome of PTC. (a) Expression levels of LPCAT2, ACOT7, HSD17B8, PDE8B, and ST3GAL1 were compared among NT tissues, PTCs, and PDTCs/ATCs in the combined GEO cohort. ***P < 0.001. (b) ROC curve analyses for the predictive values of five-gene signature risk score for dedifferentiation in the TCGA cohort and the combined GEO cohort. (c) Linear correlation analyses of the metabolic signature with thyroid differentiation genes. NIS, sodium iodide symporter; TG, thyroid globulin; TPO, thyroid peroxidase; TSHR, TSH receptor. (d) LPCAT2 and ST3GAL1 were tested for DFS analyses in patients with thyroid cancer on the Web site of gene expression profiling and interactive analyses.