We found that the formylated peptide fMLF, by binding FPR1, induces two time- and source-distinguishable waves of ROS production in CRC cells: a first rapid mitochondrial-derived ROS production (mROS), followed by a second late wave, dependent from the first, due to the activation of NADPH oxidase 1 (NOX1). This evidence concerns the gene NOX1 and colorectal carcinoma.