can you identify these data fields?

I want to know the column identifiers for this table of data.
http://www.pnas.org/content/104/28/11694/suppl/DC1#DS

The first two columns are obviously "disease 1" and "disease 2", but I can't figure out the remaining numeric values, N1-N6.  I've found the following range of values for each column, if that helps decipher their purpose.
N1: 0 - 86,355.882  (3 decimal places)
N2: 0 - 453.098  (3 decimal places, although the majority of values are just zero)
N3: 0 - 135,775 (integer)
N4: 0 - 135,833 (integer)
N5: 0 - 17,392 (integer)
N6: 0 (integer, all values are zero)

The abstract is provided at the link below, with full text (html or pdf) available in a column to the right.
http://www.pnas.org/content/104/28/11694.abstract

Any ideas?  Some of their graphs are interesting, but I want to redo one of them in particular to make it easier to examine.