Nevertheless, cofilin‐induced modulation of actin dynamics in CECs has been shown to promote transendothelial migration of breast cancer cells and formation of brain metastases in vivo.21 According to the study of Tominaga et al,21 breast cancer‐derived extracellular vesicles containing miR‐181c promote destruction of BBB TJs through reorganization of actin, via down‐regulation of 3‐phosphoinositide‐dependent protein kinase‐1 (PDPK1) and down‐regulation of phospho‐cofilin (i.e. activation of cofilin). Here, PDPK1 is linked to breast carcinoma.