Kwayoyin ciwon daji ( CSCs ), ya kasan ce kuma sune kwayoyin ciwon daji (wanda aka samo a cikin ciwace-ciwacen daji ko ciwon daji ) waɗanda ke da halaye masu alaƙa da kwayoyin halitta na al'ada, musamman ikon haifar da duk nau'in tantanin halitta da aka samu a cikin wani samfurin ciwon daji. Saboda haka CSCs suna da ƙari (tumor-forming), watakila ya bambanta da sauran kwayoyin cutar kansa marasa tumorigenic. CSCs na iya haifar da ciwace-ciwace ta hanyar tsarin ƙwayoyin cuta na sabuntawar kai da bambancewa cikin nau'ikan tantanin halitta da yawa. Irin waɗannan ƙwayoyin ana tsammanin zasu ci gaba da kasancewa cikin ciwace-ciwacen ƙwayar cuta a matsayin jama'a daban-daban kuma suna haifar da koma baya da metastasis ta hanyar haifar da sabbin ciwace-ciwace. Sabili da haka, haɓaka takamaiman hanyoyin kwantar da hankali da aka yi niyya a CSCs yana riƙe da bege don inganta rayuwa da ingancin rayuwar marasa lafiyar cutar kansa, musamman ga marasa lafiya da cututtukan metastatic . Maganin ciwon daji da ake da su galibi an haɓaka su ne bisa nau'ikan dabbobi, inda aka yi la'akarin hanyoyin kwantar da hankali don haɓaka haɓakar ƙwayar cuta.