pSTAT3 selectively associates with the raft PAG/Lyn complex in B-NHL lines and lymphomas. (A) Raft (R) and nonraft (NR) material (100 μL) of the indicated cell lines was IP with anti-PAG C-1 antibody (same material as in Figure 3A) and probed with anti-pSTAT3 antibody. (B) Raft material from SUDHL6 was IP with protein A/G-bound anti-Lyn, anti-pY505 Lck, or anti-pY418 Src antibodies, and the IP material probed with anti-pSTAT3 (first row) and anti-Lyn (second row). (C) TX-100–resistant raft material isolated from frozen lymphoma tissues was treated with 50 mM OTG and IP with Sepharose-bound anti-PAG C-1 antibody. The IP material was probed with anti-PAG MEM-255 (top), anti-pSTAT3 (middle), and anti-Lyn (bottom). (D) Same material as in panel C: WB with anti-Src pY418, anti-Lyn, and anti-Lck pY505. pSTAT3 association with Lyn/PAG was ascertained at least 3 times for all cell lines, and IPs with patient material carried out twice with lymphomas of each type.