CGIdb 2.0 is an updated database of comprehensively published genetic interactions (GIs) gene pairs, encompassing synthetic lethality and synthetic viability. CGIdb 2.0 has more reliable GIs information and some new features. (i) CGIdb 2.0 adds quantitative chemical-genetic interaction data in various cancer cell lines. (ii) CGIdb 2.0 interprets GIs by integrating protein-protein physical interaction data. (iii) CGIdb 2.0 proposes within-protein complex model and between-protein complex model to reconcile genetic and physical interactions. (iv) CGIdb 2.0 expands synthetic viability gene pairs in multiple cancer types. (v) CGIdb 2.0 predicts sensitive and resistant signature of drugs based on large-scale CRISPR/Cas9 or shRNA screens and pharmagenomic data.