The loss of TSP1 expression that has been documented to result from loss of tumor suppresser genes and activation of oncogenes associated with colon carcinogenesis could contribute to promoting early and late stages of colon tumor formation.4 Thus, ApcMin/+:Thbs1−/− mice could be useful to identify TSP1-independent effects of cancer genes on cancer progression. The gene discussed is THBS1; the disease is cancer.