However, analysis of conditional SHIP1 mutant mice showed that osteoporosis results from SHIP1 deficiency in the mesenchymal stem cell compartment that is defective for differentiation to bone-forming osteoblasts in the absence of SHIP1 expression and increased PI3K/AKT signaling that promotes a β-Catenin/Id2 transcriptional circuit [85]. The gene discussed is INPP5D; the disease is osteoporosis.