 Production is optimal at pH's close to neutral and when magnesium levels are low, and is further amplified by high concentrations of "S. aureus", which indicates its importance in establishing infection.TSST-1 differs from other PTSAgs in that its genetic sequence does not have a homolog with other superantigen sequences.TSST-1 does not have a cysteine loop, which is an important structure in other PTSAgs, and in fact it does not have any cysteine residues at all.