CD79A and B-cell non-Hodgkin lymphoma: The cytoplasmic domains of both Igα and Igβ contain an immunoreceptor tyrosine-based activation motif (ITAM) and mediate Ca2+ mobilization; however, only Igα mediates protein tyrosine kinase activation and interleukin-2 expression (e.g., in B-cell lymphoma) (7).