A method for screening for modulators of the secretion by an osteoclast of a wnt or a wnt signal enhancer comprises exposing osteoclasts in culture to a compound to be screened, exposing a wnt sensitive detection system to conditioned medium from said osteoclast culture, and determining whether a wnt signal is present in said medium by assaying for wnt mediated activation of bone formation by osteoblasts or by wnt mediated activation of LRP5 and or LPR6 signalling in a cell by detection of ß catenin or detection of translocation of dishevelled, axin, or Fratl to the cell membrane of said cell.
