Human Whartons jelly stem cells (hWJSCs) are derived ethically in large amounts from the umbilical cord matrix. Besides their differentiation capabilities, WJSCs also display a notable lack of ability to form teratoma. hWJSCs have been shown to exert immunomodulatory effects and have recently been reported to kill or diminish cancer cell growth. These characteristics are important considerations for their use in cell therapy. In this transcriptome analysis, hWJSCs were profiled using Affymetrix DNA microarrays and compared to a panel of human stem cells and stromal cells. Although hWJSCs are multipotent, they expressed very low levels of the majority of stem cell markers, including POU5F1, NANOG, SOX2 and LIN28. BIRC5 has recently been shown to be required for teratoma formation in SCID mice. The lower levels of BIRC5 expression in hWJSCs compared to hESCs and the very low levels of stem cell markers might account for hWJSCs inability to form teratomas. IL12A which is known to be associated with the induction of apoptosis, was amongst the several cytokines identified to be significantly upregulated in hWJSCs. The ability of hWJSCs to compliment the host immune responses was further highlighted with the GO Biological Process analysis showing high association with immune system, chemotaxis and cell death. The ability to modulate immune responses confers hWJSCs an additional advantage in stem cell therapy and potentially allows hWJSCs as a form of treatment for cancer and immune disorders. In summary, the transcriptome profile of hWJSCs has provided indications on the genetic basis for their biological characteristics in immunomodulatory response, anti-cancer effects, and the lack of teratoma formation.