CDKN2A and osteoporosis: To determine whether 1,25(OH)2D exerts anti‐osteoporosis action by blocking the p16‐cell senescence pathway, wild‐type and 1α(OH)ase−/− mice were fed a high calcium/phosphorus rescue diet or aged 1α(OH)ase−/− mice or 18‐month‐old aged wild‐type mice were subcutaneously injected with 1,25(OH)2D3.