Because CCM‐associated cardiovascular defects in mouse and zebrafish models have been linked to an activation of the MEKK3‐MEK5‐ERK5 signaling pathway (Zhou et al, 2015; Cuttano et al, 2016) and elevated levels of KLF2 (Renz et al, 2015; Zhou et al, 2015, 2016), we next tested the molecular effects of IR3mo treatment on these phenotypes in different CCM models. Here, MAPK7 is linked to cerebral cavernous malformation.