Gill et al. have reported SDH-deficient renal carcinomas from 27 patients and estimated that 0.05%–0.2% of all carcinomas are SDH deficient; 94% of these tumors displayed the typical morphology of SDH-deficient renal cancers; all the patients performing a genetic evaluation displayed germline SDHB mutations (only in one patient SDHA mutations were detected); a part of these patients had a metastatic disease, associated with high-grade nuclear atypia or coagulative necrosis [42]. This evidence concerns the gene SDHB and carcinoma.