 The article proposes a new reference model called zero interaction potency, ZIP, to classify drug combinations as synergistic or antagonistic. ZIP captures drug interaction relationships by comparing the change in potency between individual drugs and their combinations using a delta score to quantify deviation from expectation. The authors demonstrate that a delta score of zero implies both probabilistic independence and dose additivity and use data from an anti-cancer drug combination experiment to show that ZIP accurately captures synergy while keeping false positives low. Additionally, the article suggests using an interaction landscape over the full dose response matrix to identify and quantify synergistic and antagonistic dose regions, which may improve understanding of drug combinations mechanisms of action for clinical translation. This article was authored by Bugvanyadov, Krzysztof Wennerberg, Tarou Ato-Kelio, and others. We are article.tv, links in the description below.