SOST and osteogenesis imperfecta: Using solid tissue isolates from human OI bone patients in vitro, SclAb activates downstream Wnt targets of WISP1 and TWIST1 and induces a compensatory response in SOST and DKK1 expression, consistent with preclinical studies of OVX rats and SOST and DKK1 in female Balb/c mice.