MAPK3 and cerebral cavernous malformation: To overcome this limitation, we generated a slow progression model (i.e. chronic) of Ccm3−/− CCM by giving a low dose of tamoxifen to these Cdh5(PAC)-Cre-ERT2/Ccm3f/f mice (Fig. 2 and Supplementary Movie 7), and we analysed them at different developmental stages (i.e. P8, P14 and P30).