HPK1-IN-16 is a potent and selective inhibitor of HPK1. Hematopoietic progenitor kinase 1 (HPKl) originally cloned from hematopoietic progenitor cells is a member of MAP kinase kinase kinase kinases (MAP4Ks) family. HPK1-IN-16 is useful in researching, preventing or ameliorating diseases or disorders associated with HPK1 activity such as cancer (extracted from patent WO2019051199A1, compound 39).