TP53 and sarcoma: Because mutation of Trp53 or Cdkn2a is sufficient to initiate sarcomagenesis with expression of endogenous KrasG12D 19, we next investigated whether mutation of the identified candidate genes could induce primary sarcomas in KrasLSL-G12D/+; Rosa26L°xP-Cas9-EGFP/+ (K-LoxP-C) mice.