HPK1-IN-2 dihydrochloride is a potent and orally active hematopoietic progenitor kinase-1 (HPK1) inhibitor ( IC 50 <0.05 µΜ) with antitumor activity. HPK1-IN-2 dihydrochloride also inhibits Lck (0.05 µΜ< IC 50 <0.5 µΜ) and Flt3 ( IC 50 <0.05 µΜ) kinase activities.