A method of reducing the potential of pluripotent stem cells to generate teratomas in a subject is provided.The method comprises:(a) transplanting a cell population which comprises the pluriptotent stem cells into the subject and(b) contacting the pluripotent stem cells with an agent that downregulates an activity and/or expression of a polypeptide selected from the group consisting of AW262311 (aka SerpinB6), COX6A1, ZIC2, SOX2, M14087, OTX2, TUBB2B, IL17RD, TMSL8, CRABP1, ZIC3, CDC20, SBK1, TOP2A, DLG7, PTPRZ1, NUF2, NEFL, SPAG5, LOC146909 and survivin (BIRC5), thereby reducing the potential of the pluripotent stem cells to generate teratomas.Methods of treating tumors and compositions capable of same are also provided.
