Fig. 1. Accelerated and increased skin carcinogenesis in TSP-2-deficient mice. (A) Earlier and increased incidence of papillomas (>1 mm) in TSP-2-deficient mice (n = 24; filled squares), as compared with wild-type mice (n = 25; open circles). Incidence is expressed as the percentage of mice with detectable tumor formation during the 20 weeks of topical PMA application. (B) Significantly increased frequency of papilloma (>1 mm) formation, expressed as the average number of papillomas per mouse, in TSP-2-deficient mice (P <0.001 after 10 weeks of PMA treatment). (C) Earlier and increased incidence of large papillomas (>3 mm) in TSP-2-deficient mice. (D) Increased average number of large papillomas (> 3 mm) per mouse in TSP-2-deficient mice; P <0.01 after 13 weeks; P <0.001 after 17 weeks. (E) Increased incidence of squamous cell carcinomas (SCC) in TSP-2-deficient mice. (F) Comparable rate of malignant conversion of papillomas to SCC in TSP-2-deficient and wild-type (WT) mice.