Ewing Sarcoma PDX Models.

Ewing sarcoma (EWS) is a rare malignant pediatric tumor, and patient-derived xenografts (PDXs) could represent a possibility to increase the number of available models to study this disease. Compared to cell-derived xenografts (CDX), PDXs are reported to recapitulate better tumor microenvironment, heterogeneity, genetic, and epigenetic features. They are considered reliable models due to their superior predictive value when comparing preclinical efficacy and treatment response in patients. In this chapter, we extensively describe a method for generating EWS PDX models, along with their validation and molecular characterization.