One notable example is the STEMVAC trial, a DNA plasmid-based vaccine encoding five antigens [Mouse Double Minute 2 Homolog (MDM2), YBX1, SRY-Box Transcription Factor 2 (SOX2), Cell Division Cycle 25B (CDC25B), Cluster of Differentiation 105 (CD105)] associated with breast cancer stem cells [138]. The gene discussed is SOX2; the disease is breast cancer.