Subependymal nodules (SEN) appear deeper within the brain, affecting 68% and 78% of TSC1 and 2 patients in their respective groups, and subependymal giant cell astrocytoma (SEGA) were detected with even smaller prevalence at 32% and 26%, respectively (Fig. 4A). The gene discussed is TSC1; the disease is astrocytoma (excluding glioblastoma).