CTSG and neoplasm: Creation of a xenograft model involves transfer of tumor fragments from a live patient’s primary tumor or metastatic site into immune compromised mouse strains, most frequently NOD (non-obese diabetic) scid (severe combined immunodeficient) or NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ strains (NOD scid gamma, NSG).