Table 1

The number of spontaneously developing lung tumors in each knockout mousea

Experiment 1Male0.2 (1/5)0 (0/3)1.0 (5/8)0 (0/3)
Female0 (0/2)0 (0/5)0.33 (1/6)0 (0/3)
Total0.14b (1/7)0 (0/8)0.71b,c (6/14)0c (0/6)
Experiment 2Male0.1 (1/10)NDd0.6 (3/5)ND
Female0.1 (1/10)ND0.67 (3/6)ND
Total0.1e (2/20)ND0.64e (6/11)ND
  • a The mice were grown under special pathogen-free conditions and then were examined at 580 (±1) days (experiment 1) or between 69 and 75 weeks (experiment 2) after birth to identify spontaneously developing tumors. Tumors were scanned by macroscopic procedure over the whole lungs and then confirmed by microscopic analyses. To avoid the confusion in diagnosis, both adenomas and carcinomas are counted as tumors. Mean lung tumors/mouse for each knockout mouse is shown. The number of lung tumor-bearing mice/total mice is indicated in parentheses. Statistical differences were examined using Student’s t test (StatView 5.0J, SAS Institute, Inc.).

  • b,c P < 0.01.

  • d ND, not done.

  • e P < 0.02.