PSTPIP2 and bacterial arthritis: First, an established mouse model of osteomyelitis carries a genetic risk locus known as Pstpip2 (Proline-serine-threonine phosphatase-interacting protein 2) [17], whose human ortholog PSTPIP1 (CD2BP1) is an autosomal dominant cause of the hereditary autoinflammatory PAPA syndrome (pyogenic arthritis, pyoderma gangrenosum, acne) [18], a disease characterized by autoinflammatory bone inflammation [12, 19].