FACS analysis of lymphoma vascular cell populations. (A) Quad-gate analysis of the EL4 tumor-associated cells. Murine EPCs (mCD45⁻VEGFR2⁺CD117⁺), mature ECs (mCD45⁻VEGFR2⁺CD31⁺), murine PPCs (mCD45⁻CD140b⁺CD117⁺), and mature PCs (mCD45⁻CD140b⁺NG2⁺) are shown. Blue-dotted squares outline individual quad-gates for EPCs, PPCs, ECs, and PCs. (B) Quantification of stromal cell populations in EL4 tumors treated with imatinib vs PBS. *P < .05 compared with control.