2 vitamin_a
      2 ubidecarenone
      2 tretinoin
      2 tazarotene
      2 tamibarotene
      2 sobuzoxane
      2 retinol
      2 pimobendan
      2 nafamostat
      2 isotretinoin
      2 holin
      2 gabexate
      2 everolimus
      2 ergocalciferol
      2 enfuvirtide
      2 docosanol
      2 dihydrotachysterol
      2 colecalciferol
      2 cholesterol
      2 cholecalciferol
      2 cetraxate
      2 caspofungin
      2 candicidin
      2 cabazitaxel
      2 bacitracin
      2 anidulafungin
      2 acitretin
      2 3-(octadecyloxy)-1comma2-propanediol