HPK1-IN-28 is a potent inhibitor of HPK1. Hematopoietic progenitor kinase 1 (HPK1) is a negative regulator of the activation response of dendritic cells (DCs), T cells and B cells. HPK1-IN-28 enhances the body's anti-tumor immunity. HPK1-IN-28 has the potential for the research of immune-related diseases, especially tumor (extracted from patent WO2021175270A1, compound 1).