Immunohistochemical analysis of 3MC-fibrosarcomas.

aMost tumors strongly positive for p53, lacked p21 expression (reflecting a non-functional mutant p53); and, tumors negative or weakly positive for p53, had detectable p21 (reflecting a functional p53)
bThe few tumors that lacked Arf were negative or weakly positive for p53 (reflecting a functional p53)

a) 多数p53强阳性的肿瘤不表达p21，提示其p53为功能失活的突变体；而p53阴性或弱阳性的肿瘤可检测到p21表达，提示p53功能正常。
b) 少数缺失Arf的肿瘤呈p53阴性或弱阳性，提示p53功能正常。