CTLA4 and Abnormal intestine morphology: Diseases affecting CTLA-4 expression (CTLA-4 haploinsufficiency and LRBA/DEF6 deficiencies) may be treated with replacement of CTLA-4 protein in the form of abatacept or belatacept, with good clinical response, particularly for enteropathy or lymphoid cell-infiltrative disease of the lungs or nervous system (35, 36).