TJP1 and breast cancer: Our study furthers elucidates these inconsistencies by demonstrating that: (a) HC strengthens the BCSFB through increased Claudin‐5 and ZO‐1 expression; (b) breast cancer cells preferentially migrate through the BCSFB over the BBB; (c) HC increases the migratory nature independent of barrier resistance of metastatic breast cancer cells; and (d) HC increases metastatic breast cancer cell transmigration across the BCSFB.