PolyP levels are reduced in Ip6k1^−/− platelets. (A) Estimation of polyP levels in platelets isolated from WT and Ip6k1^−/− mice, expressed in terms of phosphate monomers (Pi). Symbols represent each animal, and lines indicate the mean polyP level in each group. (B) Platelet ADP and ATP levels in WT and Ip6k1^−/− mice. Data are mean ± standard error (n = 5 mice of each genotype). P values are from a 2-tailed Student t test (*P ≤ .05; n.s., not significant, P > .05).