To extend our observations on tumor cell lines other than HEK and Jurkat cell lines, we further examined the requirement for CTPS1 and CTPS2 for cell growth and survival of a large number of tumor cell lines from different tissues using data from the Project Achilles CRISPR-based genome-scale loss-of-function screening (34, 35Preprint, 36Preprint, 37). The gene discussed is CTPS1; the disease is neoplasm.