Table 1.

Skin tumor susceptibility by DMBA/TPA in p16 and/or p21 knockout mice

Mouse genotype
Wild-type (n = 18)p16−/− (n = 13)p21−/− (n = 13)p16−/−;p21−/− (n = 19)
Tumor type, n*
    Low-grade papilloma16542
    High-grade papilloma1571
    High-grade papilloma with microinvasion0021
    Carcinoma in situ1101
    Squamous cell carcinoma0208
    Malignant spindle cell tumor0006
Mice with carcinomas, %5.5623.0815.3884.21
Maximum no. of papillomas/mouse6.06.812.516.0
Malignant conversion ratio at 30 wk after DMBA (no. of carcinomas/total no. of papillomas), %0.934.551.235.92

NOTE: Tumors were analyzed 30 wk after DMBA treatment.

  • *The number of mice with the indicated tumors is shown.

  • One p16−/− mouse harbored two SCCs.

  • Two p16−/−;p21−/− mice harbored two SCCs.