ANPEP and cancer: Other cancer related pathways including proteoglycans in cancer, focal adhesion, Rap1 signaling pathway, PI3K/Akt pathway contain 2 or more genes with CTCs mutations, including IGF1R, PDGFRB, PIK3R1, and PTPN11. Since only 5 ~ 8 EpCAM(+)/CD13(+) positive CTCs were analyzed for each patient, clonal effect may affect the gross allele frequency.