Alpha Chain Disease, also known as immunoproliferative small intestinal disease, is related to heavy chain disease and alpha-heavy chain disease, and has symptoms including abdominal pain, diarrhea and fever. An important gene associated with Alpha Chain Disease is JCHAIN (Joining Chain Of Multimeric IgA And IgM), and among its related pathways/superpathways are T-cell activation SARS-CoV-2 and BCR signaling pathway. Affiliated tissues include small intestine and lymph node, and related phenotypes are immune system and hematopoietic system