Cancertreatmentfailure,drugresistance,ormetastaticrecurrencearethoughttobecausedmainlybytheexistenceofaverysmallnumberofcancerstemcells(CSCs).Thecharacteristicsofthissubgroupofcellsincludeself-renewal,tumorigenesis,multipledifferentiationandhighinvasiveness,metastasis,anddrugresistancepotential.ManystudieshavedemonstratedthatCSCsplayimportantrolesintumorgrowth,spreadandmetastaticrelapseaftertreatment,andarecloselyrelatedtotheprognosisofpatients.Fromatherapeuticviewpoint,deepinsightsintotheCSCsbiology,developmentofspecifictherapeuticstrategiesfortargetingCSCs,andcharacterizationoftheirmicroenvironmentcouldbeanidealwaytocombatcancer.
