IP6K1 is expressed in platelets and megakaryocytes. (A) Western blot analysis of lysates prepared from WT and Ip6k1^−/− platelets pooled from 3 mice of each genotype, using an antibody against IP6K1. GAPDH was used as a loading control. The blot is representative of 3 independent experiments. (B) Immunohistofluorescence analysis of IP6K1 expression (green) in femur bone marrow sections. Nuclei are counterstained with propidium iodide (red). Images were acquired by confocal microscopy (LSM 510 META; Carl Zeiss) using a 63×/1.4NA objective (Carl Zeiss). To improve visualization of IP6K1 staining (green), images were subjected to a 10% linear increase in brightness using LSM Browser (Carl Zeiss), and nonlinear adjustment of contrast and tonal range using Adobe Photoshop (level adjustment). Scale bars represent 10 µm.