Evi1^KI/+ mice show decreased platelet count with age. (A) Peripheral blood cells of Evi1^+/+ and Evi1^KI/+ age- and sex-matched littermates (Evi1^+/+, n = 10; Evi1^KI/+, n = 10). The platelet count of Evi1^KI/+ mice was significantly lower than that of Evi1^+/+ mice at 16, 30, 40, and 50 weeks of age. Threshold significance level, P = .05 (2-tailed Welch t test). Underlined numbers denote the P value. Values are the mean ± SEM of each group.