The first involved a case of SDH-deficient RCC that was found to possess a somatic homozygous deletion of 9 SDHA exons,10 while the second involved a somatic single nucleotide splice site alteration.11 It is intriguing that neither of these reports describe the classic paradigm of a biallelic germline plus somatic mutation that we describe here, and that follows for all previously reported SDH-deficient RCCs.5 It is currently unclear whether this represents a true SDHA-specific anomaly or is simply the result of our limited current understanding of the genetic basis for SDHA loss. This evidence concerns the gene SDHB and renal cell carcinoma.