More recently, infliximab and adalimumab (anti-tumour necrosis factor alpha) have been approved for use in patients with moderate-to-severe CD, natalizumab (anti-alpha-4 integrin) has been rejected in Europe for the treatment of CD (regulatory evaluation is ongoing in the USA) and a number of other biological therapies are in development for CD [10]. Here, ITGA4 is linked to Cowden disease.