The problem that just won't go away

Do you like maps? Do you like colors? Do you like coloring maps? Do you like signed permutations? I like signed permutations because they describe genetic mutations. I also like the fact that maybe, just maybe, there's a connection between mutations and how many colors are necessary for map-making.

Signed permutations and the four color theorem
S. Eliahou, C. Lecouvey