Indeed, we found that KRas;rank+/+ male mice survive significantly longer and have markedly less tumor burden than KRas;rank+/+ female mice at both 6 and 12 wk; in contrast, these survival differences were much less pronounced—with a comparable tumor burden at 6 and 12 wk—among KRas;rankfl/fl female and KRas;rankfl/fl littermate male mice (Fig. 7A,B). Here, KRAS is linked to neoplasm.