The authors suggested that these genes may influence the regional pattern of volume loss and, thus, the disease phenotype; for instance, patients with MAPT and CXCR4 susceptibility variants may have a higher risk of developing PSP, while patients with MAPT, MOBP, and GLDC may be at greater risk for CBD/CBS or FTD than PSP. This evidence concerns the gene CXCR4 and red-green color blindness.