PTGS2 and cancer: Concurrent targeting of COX-2 and EP1/EP4 has been reported to have anti-cancer effects due to the simultaneous inhibition of viral and non-viral mediated tumorigenic mechanisms acting at multiple levels such as viral-host protein interactions, host and viral gene expression through regulation of epigenetic mechanisms such as methylation, host signaling, immune system activation, pro-inflammatory and cell survival processes (Paul et al., 2013a).