The fact that in colorectal cancer, on one hand, H2S and polysulfides are overproduced, and on another hand, CyR61 is overexpressed, led us to speculate that increased H2S levels, due to the induction of various H2S-producing enzymes in cancer cells, may induce or activate CyR61, which, in turn, may contribute to cancer aggressiveness. This evidence concerns the gene CCN1 and cancer.