The degree of combination synergy (or antagonism) is quantified by comparing the observed compound combination response against the expected response, calculated using a reference model that assumes no interaction between compounds. The commonly-used reference models include the highest single agent (HSA) , Bliss , Loewe and Zero interaction potency (ZIP) model . In this study, different synergy metrics such as gamma (𝛾𝛾), beta, and Excess HSA were analyzed to measure the degree of reproducibility of duplicated combinations.