Table 6 shows the magnitude of differential expressions (tumor vs. normal) of the genes that were significantly different among these four categories of CRC patients. From a 5-FU therapeutic point-of-view, the result suggests that (a) CRC patients with MSI, and more specifically MSI with KRAS mutation may benefit from therapy that can reduce TYMS or BUB3 expression; and from therapy that can enhance NQO1 expression; and (b) CRC patients with MSS irrespective of KRAS mutation status may benefit from therapy that may increase SMAD4 expression. The gene discussed is SMAD4; the disease is colorectal carcinoma.