Claim: The prostaglandin EP4 receptor is similar to EP2 and is subject to homologous desensitization which makes it oversensitive and increases its ability to stimulate cells.
Evidence: Following its activation, EP4 undergoes homologous desensitization. That is, EP4 becomes insensitive to further activation and internalizes. This effect limits the duration and extent to which EP4 can stimulate cells.