BTK and immunodeficiency disease: Previous studies are not focused on the identification of specific molecular targets triggering improvements in humoral immunity although our data show several potential key genes for this interaction, such as Blnk coding for the B-cell linker protein, essential in the B-cell development and B-cell antigen receptor signaling pathway (37), and Btk gene coding for Bruton’s tyrosine kinase involved in pre-B-cell receptor signaling, survival of immature B cells in the bone marrow, and the development of peripheral B cells, both representing the primary immunodeficiency pathway (38).