JAK2 and hepatocellular carcinoma: We have reported that PTPRO can suppress hepatocarcinogenesis in mouse hepatocytes via suppression of Jak2/Stat3 and c-Src/Stat3 activation.14 We also previously reported that deletion of PTPRO truncated (PTPROt) decreased the quantity and quality of cytotoxic T lymphocytes (CTLs) in a mouse HCC model.22 Therefore, we doubted that the deletion of PTPRO in macrophages would suppress CTLs via PD-L1–induced T-cell exhaustion.