Therefore, since the PfEMP1 product appeared on the iRBC surface at ∼16 hr post invasion [52], it is rational to speculate the dominant var transcripts in rings, including the uspA vars, would be responsible for the cytoadhesion phenotypes in the late stage, which is consistent with our observation that the higher transcription level of uspA vars in rings is linked to the higher parasitemia in vivo and ICAM-1-binding in vitro. This evidence concerns the gene VARS1 and parasitic infectious disease.