Time-resolved Förster Resonance Energy Transfer Assays for Measurement of Endogenous Phosphorylated STAT Proteins in Human Cells.

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway plays a crucial role in mediating cellular responses to cytokines and growth factors. STAT proteins are activated by tyrosine phosphorylation mediated mainly by JAKs. The abnormal activation of STAT signaling pathways is implicated in many human diseases, especially cancer and immune-related conditions.