Apologies for the naive question but I am new to the field of Position Frequency matrices (PFMs). I am trying to find a PFM for CTCF binding in the mm9 version of the mouse genome...
I have searched JASPAR, TRANSFAC and http://ccg.vital-it.ch/pwmtools/pwmbrowse.html. None of the databases in these websites return a verifiable PFM for CTCF in the mm9 genome.
I also tried the R-packages TFBSTools, JASPAR2014 and JASPAR2016.
opts <- list(name="CTCF", species = "10090")
pfm <- getMatrixSet(JASPAR2014, opts)
And this returns 0 results.....
Does anyone know where I can get a PFM for CTCF in mm9?