VEGFA and colorectal carcinoma: When comparing to CK20-positive cells detection by IHC [11, 44], VEGF-A mRNA detection by RT-PCR is more powerful to predict CRC patients’ prognosis because currently the interpretation of IHC staining for CK20-positive cells are not standardized [44] and the number of CK20-positive cell is too small to reflect the clinical status of the patients.