CTCF interacts with the lytic HSV-1 genome to promote viral transcription.

Importantly, ChIP-seq analysis revealed that there is a higher level of CTD Ser2P modified RNA Pol II near CTCF peaks relative to the Ser5P form in the viral genome. These suggest that CTCF promotes HSV-1 lytic transcription by facilitating the elongation of RNA Pol II and preventing silenced chromatin on the viral genome.

For the study's cell samples, Countstar (model not specified) provided cell-count measurements during growth assessment in the 2017 Scientific reports study.