Based on the correlation observed between the levels of CK19 expression and the age of the patient, we chose four regular CRC cell lines (SW480, from a 50-year-old male; LS 174T, from a 58-year-old female; LoVo, from a 56-year-old male; HT-29, from a 44-year-old female) from donors who were all under the age of 60 and determined their endogenous levels of CK19 expression (40 KDa) using an immunoblot analysis (Figure 3). The gene discussed is KRT19; the disease is colorectal carcinoma.