 Several related thio and seleno anions are known including (A = alkali metal cation, [PPh4]+, [NEt4]+)
More complex tetrahedral anions include A2[MoS4−xOx] and A2[WS4−xOx]

Ammonium tetrathiomolybdate was first used therapeutically in the treatment of copper toxicosis in animals.It was then introduced as a treatment in Wilson's disease, a hereditary copper metabolism disorder, in humans; it acts both by competing with copper absorption in the bowel and by increasing excretion.Clinical studies have shown ATTM can effectively lower copper levels faster than currently available treatments, and that fewer patients with an initial neurological presentation of their disease who are treated with ATTM experience neurological deterioration 

Various phase II clinical trial of ATTM for copper depletion in cancer have been performed.