In addition, the first intron of the porcine [beta]-casein gene contained transcriptional enhancer Oct-1, SRY, YY1
, C/EBP [beta], AP-1, and the retroviral TATA box.
performed a genomewide association study in the Icelandic population by analyzing parental-origin-specific effects, thereby identifying a new candidate SNP close to YY1
associated protein 1 (YY1AP1) (52).
Several host cell transcription factor binding sites and keratinocytes specific enhancers like AP-1, Sp1, NF-1, TEF-1, TEF-2, Oct-1, AP-2, KRF-1, YY1
, STAT3 and glucocorticoid responsive elements have been identified in the upstream regulatory region (URR) of HPV, which determine the cell-type-specific viral gene expression and contribute to the tissue tropism of HPV (20,21).