The human Otk orthologue was originally named Colon Carcinoma Kinase 4 (CCK4), a gene highly upregulated in colon cancers, but was renamed Protein Tyrosine Kinase 7 (Ptk7) because its protein structure places it among a single-pass transmembrane receptor family with a deficient kinase domain [36,37]. The gene discussed is PTK7; the disease is malignant colon neoplasm.