There are other factors involved in tumor development, progression, and poor prognosis in colorectal cancer, assessed as targets for immunoPET in preclinical studies for the detection of colorectal cancer cell lines, including HER3 (69), angiogenesis factors [VEGFR (161) and PDGFRβ (82)], and hypoxia (M75 targeting carbonic anhydrase-IX [CA-IX]) (40, 207). This evidence concerns the gene CA9 and colorectal cancer.