Based on the model for GPX1/2 action relative to the postulated PRDX relay (Figure 1), the main factors in CRC are ROOH signaling, in which NOX1 may have a major role, the GPX:PRDX ratio that would modulate the ROOH signaling potential, and the protein expression pattern of the cell type that would dictate the response to the ROOH signal. Here, GPX1 is linked to colorectal carcinoma.