CYP21A2 and neoplasm of testis: In 1940, Wilkins et al. reported that testicular tumors occurred in male patients with CAH due to CYP21A2 deficiency, known as so-called testicular adrenal rest tumors (TART).11 During the embryological period, steroidogenic cells that are destined to become adrenal and gonadal cells derive from neighboring areas of the coelomic epithelium and are morphologically identical.