Additionally, a study that performed WES on 28 paired tumor samples collected from the same patients who were unresponsive to chemoradiotherapy before and after treatment demonstrated that recurrent mutations in CTDSP2, APC, KRAS, TP53, and NFKBIZ confer a selective advantage to cancer cells, leading to resistance against chemoradiotherapy treatment. The gene discussed is APC; the disease is neoplasm.