ERK2 Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Phosphotyrosine Fyn JNK1 Lck Lat NF-kB ZAP-70 PKC CD4 Slp-76 IkB PKC TCR CD3 MHC Class II ITK and TCR Signaling