INS and cancer: I have described a transporter-conscious drug design for crossing the cell membrane based on carrier-mediated transport [5], delivery of substances into cells across the membrane using cell-penetrating peptides through endocytosis or direct translocation [6], drug internalization into cancer cells that express specific proteins to avoid off-target side effects in cancer therapy [7], substance delivery into the brain across the blood–brain barrier (BBB) based on transcytosis [8], and intranasal conjugated substance delivery into the brain using insulin as a carrier [9].