YTHDF3 and breast cancer: Specifically, YT521‐B homology N6‐methyladenosine RNA binding protein F3 (YTHDF3) and the 2,6‐sialic acid transferase (ST6GALNAC5) were recently proven to promote tumour cell BBB extravasation in breast cancer‐derived brain metastasis,23, 24 and aldehyde ketone reductase 1B10 (AKR1B10),25 placental growth factor26 and the non‐coding microRNA (miR)‐143‐3p27 were determined to facilitate lung cancer‐derived brain metastasis.