text: A mutation in this gene has been associated with hyperimmunoglobulin E syndrome (HIES), a primary immunodeficiency characterized by elevated serum immunoglobulin E.
  TYK2 appears to play a central role in the inflammatory cascade responses in the pathogenesis of immune-mediated inflammatory diseases such as psoriasis. The drug deucravacitinib (marketed as Sotyktu), a small-molecule TYK2 inhibitor, was approved for moderate-to-severe plaque psoriasis in 2022.
  The P1104A allele of TYK2 has been shown to increase risk of tuberculosis when carried as a homozygote; population genetic analyses suggest that the arrival of tuberculosis in Europe drove the frequency of that allele down three-fold about 2,000 years before present.