Figure 3.

Association of JAK/STAT proteins. Immunoprecipitation (IP) was performed with the anti-phosphotyrosine antibody 4G10, and immunoblotting was performed with antibodies specific for various STAT or JAK proteins (as indicated in a–e). In the case of patient 3, protein extracts from the first sampling were used for the 4G10 IP, and those from the second sampling were used for the JAK3 IP. The amount of protein in sample 1 of patient 3 was half of that in sample 2. IP with anti-JAK3 antibodies was followed by immunoblotting with anti-STAT-3 antibody (f), anti-phosphotyrosine antibody (g), or anti-JAK3 antibody (h).