Table 2 summarizes the genotype/phenotype correlation and age of the VHL patients from which ECs were derived. V#5 presents an additional rare disease: the patient is heterozygous for CLN5 protein in the neuronal ceroid lipofuscinosis rare disease. Our group hypothesized that the CLN5 mutation in this VHL patient offers a protective effect, preventing tumor development in those tissues potentially suffering a VHL second hit mutation [24]. The gene discussed is CLN5; the disease is neuronal ceroid lipofuscinosis.