For example, azurin enters preferentially to cancer cells than to normal cells and inhibits the cancer cell growth by interfering in multiple steps in its growth such as receptor tyrosine-kinase-mediated cell signaling, EGF-EGFR-mediated angiogenesis and inducing apoptosis through stabilization of tumor suppressor p53 by preventing its ubiquitination. This evidence concerns the gene NTRK1 and cancer.