Exposure to Therapeutic BTK Inhibitors Induces Phenocopying of Mutants in the Fruit Fly .

Background: Bruton's tyrosine kinase (BTK) is a non-receptor type tyrosine kinase originally identified as the genetic signature responsible for X-linked agammaglobulinemia (XLA) when mutated. Its functional form is required for B lymphocyte maturation in both humans and mice, whereas loss-of-function causes a different form of developmental defect in the fruit fly, .

Methods: Ibrutinib and other therapeutic inhibitors of BTK have been extensively used to successfully treat various leukemias and lymphomas.