Efficient protein ablation, similar platelet phenotypes, but no altered lymphocyte counts in Csk;Gp1ba-Cre mice. (A) Protein levels of Csk and GAPDH in platelet lysates of the indicated genotypes were determined by capillary-based immunoassays with the respective antibodies. Platelet Csk protein levels were determined by normalizing Csk peak areas by GAPDH peak areas (Csk/GAPDH ratio), n = 3 to 6 mice per genotype. (B) Platelet counts and platelet volumes, n = 7 to 10 mice per genotype. (C) Platelet surface receptor expression of GPVI and G6b-B were measured by flow cytometry and shown as MFI, n = 6 to 10 mice per genotype. (D) White blood cell and lymphocyte counts, n = 9 to 33 mice per genotype. (A-D) Asterisks refer to significant difference in Csk^fl/fl;Gp1ba-Cre^+/KI or Csk^fl/fl;Pf4-Cre^+/KI mice compared with Csk^+/+;Gp1ba-Cre^+/KI or Csk^+/+;Pf4-Cre^+/KI mice, respectively (***P < .001; 1-way ANOVA with Sidak’s test); data represent mean ± SD.