Using the TCGA PanCancerAtlas for Mutual Exclusivity analysis of pan-cancer mutations, we uncovered cooccurrence relationships of THBS2, THBS4, and THBS5 with THBS1; THBS4, THBS3, and THBS5 with THBS2; and THBS3 and THBS4 with THBS5. Here, THBS3 is linked to cancer.