GP6 and cancer: Previously, bosutinib has been reported to have fewer and milder off‐target activities.3 However, bosutinib can upregulate mitogen‐activated protein kinase (MAPK) in cancer cells.51 In platelets, MAPK is directly linked to GPVI‐mediated signaling.52 Increased activation of MAPK might explain why bosutinib treatment leads to more procoagulant platelet formation.53