In fact, 50% of serous cystadenomas contained mutations of the VHL gene; interestingly, 75% of IPMNs and about 35% of mucinous cystic neoplasms (MCNs) contained mutations of RNF43, a gene encoding for a protein with intrinsic E3 ubiquitin ligase activity, thus suggesting that this may act as a suppressor of IPMNs and MCNs [29]. The gene discussed is RNF43; the disease is lipoid nephrosis.