DOCK1 and combined immunodeficiency due to DOCK8 deficiency: As a member of the DOCK180-related protein family, DOCK8 (OMIM 611423), which contains 47 exons spanning 190 kb, is expressed in hematopoietic cells, brain tissue, the lungs, the pancreas, the kidney, and the placenta.[25] Heterozygous mutations and deletions of DOCK8 are associated with autosomal recessive hyper-IgE recurrent infection syndrome (OMIM 243700).