Publisher Summary The chapter discusses the current knowledge in the field of X-Linked
Agammaglobulinemia (XLA) in the context of the recent developments. XLA, by being the
first human disease caused by a defect in the function of a cytoplasmic tyrosine kinase (PTK)–
the XLA product designated Btk (Bruton's agammaglobulinemia tyrosine kinase)–has
attracted various investigators with interest in cellular immunology, clinical immunology,
genetics, gene therapy, structural biochemistry, and signal transduction. The clinical …