Compara.{release}.{protein|ncrna}_{species_collection}.homologies.tsv.gz
  Contains all the orthologies in a single tab-separated file.
  Each orthology is represented on one line in this format:
   gene_stable_id1 seq_stable_id1 species1 %identity1 homology_type gene_stable_id2 seq_stable_id2 species2 %identity2
  where seq_stable_id is either a protein or a transcript stable ID, depending
  on whether the gene is protein-coding or not