RPAP2 and neoplasm: Additionally, RPAP2 triggered DR5‐mediated apoptosis by dephosphorylating IRE1 under conditions of unresolved ER stress.[31] Furthermore, a recent study has demonstrated that RPAP2 facilitates the tumor‐suppressive functions of TGFβ1 in keratinocytes through the dephosphorylation of IRE1.[32] In this study, we found that RPAP2 plays a role in promoting liver tumor growth.