DEFB1 and cancer: (i) Dysregulation of HBD1 expression in certain types of cancers, (ii) the putative activity of HBD1 as tumor suppressor, (iii) the relation between cancers and the EGFR pathway, and (iv) the presence of several putative E-box DNA binding sites for MYC in the HBD1 promoter prompted us to investigate the connection between regulation of HBD1 expression and cancer signaling pathways.