In core signaling pathways of carcinogenic progression from normal thyroid cells to early-stage thyroid cancer cells shown in Figure 1, identified gene expression signature containing three abnormal downregulated genes—PDX1, JAM3, and NOV—and six abnormal upregulated genes—IL4, RAP2C, PARD6B, MAP2K1, CD151, and MAPK1. The gene discussed is MAP2K1; the disease is thyroid cancer.