Among the gene pairs displaying the lowest cdNS values, indicating an ANT relationship, we noted that RB1 and RNF43 mutation contexts are antagonistic to IDH1 missense and APC truncating mutations in gliomas and colorectal cancers, respectively (ranked 5th and 6th with cdNS scores of − 3.83 and − 3.76). The gene discussed is RB1; the disease is central nervous system cancer.