RAP1A is a type of Ras‐associated protein 1 (RAP1), with 95% sequence homology to RAP1B.15 It is a significant regulator and mediator of Ras functions, and its activation has been linked to a variety of cancers.16, 17 EPAC is a guanine nucleotide exchange factor (GEF) for the RAP1, which activates RAP1 by GDP‐GTP exchange.21, 22 Agonists and antagonists selective for EPAC have been developed and can be used for further studies on the activation of RAP1, which will increase our understanding on the signalling pathway.23 Here, RAP1A is linked to cancer.