Expression of P2RX7 mRNA, protein, and mHAg in selected tissues. (A) Immunohistochemical analysis of P2RX7 expression in human lung. The width of the image is 936 microns. (B) Expression of P2RX7 (▩) and of the P2RX7-encoded mHAg recognized by CTL clone 11C6-109 (■) in patient no. 1–derived EBV-LCL, dermal fibroblasts, leukemic blasts obtained from patient no. 1 at the time of his first posttransplantation relapse (before T-cell therapy), and leukemic blasts obtained at the time of his second posttransplantation relapse, after the receipt of 6 CTL infusions. P2RX7 expression was assessed by real-time quantitative PCR, and mHAg expression was assessed by a 4-hour ⁵¹Cr release cytotoxicity assay at an E/T ratio of 10:1.