Appendage of p85-binding sites restores Epo-induced epsin-1 co-localization of a truncated EpoR that mimics those from PFCP patients in γ2A cells. (A) Schematic diagram of PFCP and rescue EpoR constructs. (B) PFCP EpoR did not co-localize with epsin-1 upon Epo stimulation. (C) Rescue EpoR appended with p85-binding sites rescued Epo-induced epsin-1 co-localization. The arrow points to a representative co-localization area.