Fig. (6). Genetic differences in cell lines affecting phenotypic responses are detectable using subpopulation analysis HCT 116 and HeLa cells were both exposed to an inhibitor of CDK4/6 at a concentration of 313 nM for 48 hours. Heatmap analysis was then performed to differentiate the compound effects on each cell type. HCT 116 cells arrested with a primarily S phase phenotype with HeLa cells remained unaffected by this treatment.