Phosphotyrosine Phosphotyrosine Phosphotyrosine c-Jun NF-kB NF-kB Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine ERK2 Fyn Fyn JNK1 p38 MKK Lat CD4 CD8 CD28 CD45 SIT IkB SLP-76 TRIM ZAP Akt LCK MHC Class II TCR CD3 B7-1 B7-2 CTLA-4 CTLA-4 CTLA-4 CTLA-4 PKC IL-2 T-Cell Receptor Signaling