In detail, the TYK2 loss-of-function mutation was associated with decreased risk of hypothyroidism, psoriasis and its related disorders, psoriasis vulgaris, rheumatoid arthritis and other inflammatory polyarthropathies, psoriatic arthropathy, chronic hepatitis, ulcerative colitis, inflammatory bowel disease and other gastroenteritis and colitis, celiac disease, noninfectious gastroenteritis, type 1 diabetes, disorders of eye, and increased risk of congenital deformities of feet and congenital anomalies of stomach (Table 1). Here, TYK2 is linked to rheumatoid arthritis.