If IFN-free regimens are not available there should be a low threshold for obtaining tissue transglutaminase IgA from patients if diarrhea, weight loss, or anemia developed while on or after the use the interferon therapy and if the suspicion of CD is high, intestinal biopsy should be pursued even if serologies are negative and a gluten-free diet must be started preemptively. The gene discussed is IFNA1; the disease is anemia (phenotype).