C Western blot confirmation of the mitosis‐selective cell surface localization of PCDH1. Whole‐cell lysate samples were subjected to SDS-PAGE and blotted with the anti‐PCDH1, anti‐β‐actin, and anti‐phospho‐Histone H3 antibodies, as indicated on the left. Cell surface fraction samples were blotted with the anti‐PCDH1 and anti‐ EGFR antibodies. 