PTPRC and neoplasm: Since JAK signaling plays a crucial role in regulating the immune system, we analyzed if JAK1/2 inhibition affected the composition of the TME by performing flow cytometric analysis of lung tumors.17 Indeed, the abundance of tumor promoting granulocytic CD45+CD11b+LY6G+ and monocytic CD45+CD11b+LY6C+ MDSC38 was significantly reduced in the lungs of tumor‐bearing, ruxolitinib‐treated mice.