Lack of function of Bruton’s tyrosine kinase (Btk) causes X-linked agammaglobulinemia June 22, 2017 Billie Young Lack of function of Bruton’s tyrosine kinase (Btk) causes X-linked agammaglobulinemia (XLA) in humans and X-linked immunodeficiency in mice (xid). phosphorylation or a negative charge Bosutinib ... Read More