C3 and neoplasm: However, analysis of the gene knockout phenotype from genetic screens revealed that the knockout of C5 is a strong influencer of lymphocyte-mediated tumor killing in colon cancer models (Kearney 2018 NK_10 and Kearney 2018 NK_20), while C3 knockout influences lymphocyte-mediated tumor killing in the melanoma model (Manguso 2017; GVAX+PD1, Figure 6A third panel).