When compared to stimulation by toxic shock syndrome toxin (TSST)-1, a non-Vγ9+ selective reagent that activates αβ T cells, secretion of the anti-fibrotic cytokines TNFα and IFNγ in response to the Vγ9 selective antigen IPP was relatively diminished in SSc compared to HC. The gene discussed is IPP; the disease is systemic sclerosis.