We selected the CREB3L1 gene [GenBank:NM_052854.2], encoding the ER-stress transducer OASIS (Old Astrocyte Specifically Induced Substance), as an excellent candidate gene based on the observation that OASIS-/- mice were born with severe osteopenia and spontaneous fractures[29], reminiscent of severe human OI. The gene discussed is CREB3L1; the disease is Osteopenia.