Difference Between Hg19 And Uniform Background For Pwms, As Used In Hocomoco

Question

[Misty]

The HOCOMOCO TF database carries different data formats for download. I am interested in downloading the curated collection of PWMs in txt format. However, they have calculated the PWMs against uniform background as well as hg19 background. Sadly, I have no idea what that means... can anybody explain??

Thanks!

[Giovanni M Dall'Olio]

It looks like as it refers to a randomly generated background, in which the probability of observing any of the four bases is equal. However, to be sure you should better contact the authors directly.