Although Jrt mice display growth retardation, skeletal abnormalities, hypophosphatemia and increased serum FGF23 and ALP levels similar to other murine models of XLH; unlike those models Jrt osteoblasts in vitro have been observed to resemble those from wild type males with respect to cellular differentiation and calcium deposition into bone matrix [76]. This evidence concerns the gene FGF23 and X-linked hypophosphatemia.