A known variant of POT1, with D224N mutation, disrupts POT1 binding to ssDNA telomere oligonucleotides, leading to longer and fragile telomeres, predisposing for chronic leukocyte leukemia, glioma, angiosarcoma, osteosarcoma, thyroid cancer, colorectal cancer, and cutaneous melanoma [110]. The gene discussed is POT1; the disease is colorectal cancer.