CD38 and Osteopenia: In correlation with the clinical findings, the severity of every individual radiological sign considered here (soft tissue swelling, juxtaarticular osteopenia, narrowing or disappearance of the interosseous spaces reflecting cartilage loss and bone irregularities secondary to periosteal new bone formation and/or marginal articular erosions) was significantly lower in CD38 KO than in WT mice (Figure 2A and B).