RFC1 transport function is enhanced by another protein, Collagen alpha-1 (XVIII) chain, encoded by COL18A1 (locus 21q22.3), and has been described as crucial for malignant processes due to endostatin production (Digtyar et al., 2007), which is a powerful angiogenesis and tumor growth inhibitor (Sertie et al., 2000). The gene discussed is COL18A1; the disease is neoplasm.