To study the possible transformation of normal human testicular cells into malignant cells during prolonged cell culture, we generated genome-scale 5-mC profiles of ITGA6+ enriched primary testicular cells (PTC, n = 4) both before culture (d0-PTC) and after long-term culture (LT-PTC), as well as three primary seminoma lesions (SE, n = 3) (Fig 1A). The gene discussed is ITGA6; the disease is seminoma.