Exemplary illustrations of the dependence of viral entry efficiency on various tested parameters. The figure shows a graphical representation of exemplary data collected for the two reference clones (NL4-3 and NL4-3 R5) and one dual-tropic clone (685). Dependence of the entry efficiency on the surface expression levels of all receptor/coreceptor combinations (A) and on concentrations of two entry inhibitors (B) from representative experiments are shown. Concentrations of AMD and MVC are shown in ng/ml and nM, respectively. Planes traced with dashed lines were fitted using linear regression and indicate the direction of the decrease of the entry efficiency with the increase of each drug concentration.