Based on this analysis, the interaction parameter, ψ, was estimated at 0.95 and 1.27 for Huh7 and MDA-MB-468 cells, respectively, which suggested that CIS and CIM combinations were modestly synergistic or additive (ψ slightly less than 1) for OCT2-negative cell line, Huh7 while antagonistic (ψ greater than 1) for OCT2-positive cell line, MDA-MB-468. This evidence concerns the gene SLC22A2 and in situ carcinoma.