Given that GAPDH nitrosylation has been demonstrated to trigger nuclear translocation and initiate p53-mediated cell death (Hara et al., 2005), a recent article has provided the mechanism by which microcystins-LR (MC-LR), a toxin produced by cyanobacteria, induces colon cancer cells apoptosis. This evidence concerns the gene GAPDH and malignant colon neoplasm.