In parallel, sporadic RCCs with loss of function mutations in TSC1 or TSC2 have been identified, with some histologies such as eosinophilic solid cystic (ESC) and RCC with leiomyomatous stroma (RCCLS) showing high-frequency TSC1 or TSC2 mutations, and ESC-RCC is believed to be potentially pathognomonic for TSC gene mutations. Here, TSC1 is linked to renal cell carcinoma.