According to the 2020 European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) diagnostic guidelines, the most accurate and cost-effective method for initial testing for celiac disease (CD) is the combination of total Immunoglobulin A (IgA) and IgA class antibodies against transglutaminase (TGA-IgA). The gene discussed is CD79A; the disease is celiac disease.