I was wondering how important it was to remove/disavow:

1. NoFollow backlinks - many ("buy viagra" etc).
2. Directory backlinks - many questionable/generic directories.

Obviously the focus is the equity passing links but both of the above constitute a significant proportion of backlinks to the site - I've seen that "scrapers" are seen as natural and obviously NoFollow do not pass link juice - but does the sheer number have a bearing and therefore make them equally important to address?

Thanks in advance for your responses.

Regards