BLK and autoimmune disease: In search for variants in BLK- interacting proteins, we identified 2 families in which there was co-segregation in patients with autoimmune disease of a rare BLK SNV with a rare and a low-frequency mutation in B-Cell Scaffold Protein With Ankyrin Repeats 1 (BANK1) (BANK1D400G rs201960198, ExAC MAF < 0.00007 and BANK1W40C rs35978636, ExAC MAF:0.0103), respectively).