Among the most overexpressed genes in tumor cells compared to normal tissue are genes coding for transcription factors (HOXB9, SIM2, ZIC5, SP8, TFAP2A, FOXE1, HOXB13, and SALL4), cancer testis antigens (CT83), and cytokines activating regulatory Th17 cells (IL23A). The gene discussed is IL23A; the disease is neoplasm.