The expression, storage, and secretion of PIRB ligand ANGPTL2 in platelets. (A-B) The relative mRNA levels of ANGPTLs in human and mouse platelets separately (n = 5, mean ± SEM). (C) The expression levels of ANGPTL2 (A2) in human and mouse platelets. (D) Representative images of human platelets adhesion on immobilized Fg immunostained with goat anti-ANGPTL2 (A2, red) and rabbit anti-VWF (green) antibodies. Goat and rabbit IgG were used as negative controls, respectively. (E) Representative images of aggregated human platelets clots were stained with goat anti-ANGPTL2 (red), goat IgG negative control (red), and Alexa 488-phalloidin (green), respectively. (F) The effect of PE-conjugated rat anti-human LILRB2 monoclonal antibody on Alexa 488-conjugated Flag-ANGPTL2 binding to human platelets. PE-conjugated rat IgG was used as a negative control.