In the study, 231 individual persistently infected BHK-21 cells were isolated by micromanipulation after passages 28, 38, and 68 (PI28, PI38, and PI68, representing early, middle, and late infection, respectively), and were used to investigate variations in the expression levels of the FMDV virus 3D gene and the host EBP gene by sc-qRT-PCR. Here, EBP is linked to infection.