centromere to telomere orientation; Exons: 17

Transcript length: 4,419 bps

Number of residues: 620 residues; Molecular weight: 71 kDa; Conserved domains: PH-Tec, Tec pleckstrin homology (PH) domain; BTK, Brutons tyrosine kinase Cys-rich motif; SH3, Src homology 3 domains; SH2, Src homology 2 domains; TyrKc, Tyrosine kinase, catalytic domain.

Although originally described as an important component of proximal TCR signaling pathways, the Tec family tyrosine kinase Itk has become increasingly recognized for its important role in regulating T-helper-cell differentiation. Itk has a crucial role in Th2 responses, both the protective responses to pathogenic infections in addition to the pathological responses resulting in allergic asthma. Itk is not required for Th2 differentiation per se, but effector Th2 cytokine production during recall responses is severely impaired in the absence of Itk.