A similar CRISPR KO screen from project SCORE that excluded known core fitness genes of colorectal cancer, disclosed a few non-overlapping recurrent genes in colorectal cancer cell lines with 20q11.21 amplification, including DONSON (downstream of the SON gene, DNA replication fork stabilization factor), SNAP23 (synaptosome-associated protein 23) and HMGCS1 (3-hydroxy-3-methylglutaryl-CoA synthase 1). The gene discussed is SON; the disease is colorectal cancer.