For example, research analyzed data from 36 patients with CCA tissue, and 9 normal tissues obtained from The Cancer Genome Atlas (TCGA) database, which revealed that the genes VSNL1, TH, PCP4, IGDCC3, RAD51AP2, MUC2, BUB1, and BUB1B are associated with tumor progression and with the prognosis of CCA [21]. The gene discussed is PCP4; the disease is cholangiocarcinoma.