In vivo depletion of Inpp4b in mice is not sufficient to drive spontaneous tumorigenesis per se as Inpp4b−/− mice are viable with a normal lifespan and no evidence of tumour development up to 2 years of age, although mice exhibit decreased bone mass and osteoporosis from 8 weeks of age [125,126,134]. This evidence concerns the gene INPP4B and osteoporosis.