FRS2, a crucial adaptor protein of the FGFR signaling pathway is overexpressed in most WD/DDLPS suggesting involvement of the FGFR pathway in LPS tumorigenesis. Immunohistochemistry was used to perform an exhaustive analysis of the expression pattern of FGFR1-4 in WD/DDLPS both in a large collection of 421 primary tumors and in our in-house panel of validated human WDLPS and DDLPS cell lines . Cells were exposed to erdafitinib - as a single agent or in combination...We have detected a high expression of FGFR1 and/or FGFR4 in a significant percentage of WDLPS and DDLPS and demonstrated that this expression is correlated with poor prognosis.