Inhibition of GPCR or ITAM signaling in mouse platelets does not impair whole-blood (WB) clot formation in vitro. Recalcified WB was clotted with tissue factor. After 2 hours, clots were visualized and weighed. Representative images and clot weights of WB clots from mice treated with anti-GPIbα antibodies (A-B), high DAPT (C-D), or ibrutinib (E-F). Dots represent individual mice, bars indicate medians. ****P < .0001.