Since hPBMCs derived from different donors usually exhibited discrepant sensitivities, we paired the IL-2 production with or without compound treatment (0.3 μM) by each donor (Fig. ). Similarly, 7m only slightly promoted IL-2 secretion (P = 0.053), while 9h powerfully triggered IL-2 production (P < 0.001) and was more potent than 6. These results indicated the promising activity of 9h targeting HPK1 in hPBMCs.