Decreased proliferation and increased apoptosis in TrampC1 and AT-3 primary tumors upon GPVI blockade. (A) AT-3 primary tumors 18 hours after antibody treatment stained for CD31 (red), Col I (cyan), and 4′,6-diamidino-2-phenylindole (DAPI; blue). Scale bars, 100 µm. (B) For quantification of the amount of vessels with lumen, the average of 10 visual fields per mouse was calculated (n > 4). (C) AT-3 primary tumors 18 hours after antibody treatment stained for CD31 (red), Col IV (green), and DAPI (blue). Scale bars, 10 µm. (D) AT-3 primary tumors 18 hours after antibody treatment stained for CD31 (red), LMα4 (green), and DAPI (blue). Scale bars, 10 µm. Data are presented as mean ± SEM. (E) TrampC1 primary tumors 18 hours after antibody treatment stained for phospho-histone H3 (PH3) and cleaved caspase-3 (Cas3). Scale bars, 250 µm. (F) For quantification in the (left) TrampC1 model with n > 5 and (right) AT-3 model with n > 4, the average from 10 visual fields per mouse was calculated. ***P < .001, **P < .01, and *P < .05; Kruskal-Wallis with Dunn’s multiple comparisons test.