RPS3 and cancer: HSV selectivity for cancer cells has been accomplished by deletion of one or more viral genes, such as the γ134.5 neurovirulence gene [53], the UL39 viral ribonucleotide reductase (ICP6) gene [54], the US3 protein kinase gene [55,56], and/or the Us12 gene [57] whose product, ICP47, blocks MHC class I antigen presentation [58].