Interferon gamma (IFN-γ) is one of the Th1 cytokines.
Remember:
Th1 cytokines = IL-2, IL-12, IFN-γ
Th2 cytokines = IL-4, IL-10
Being one of the Th1 cytokines makes IFN-γ a little different to IFN-α and IFN-β, because IFN-α and IFN-β are induced by local triggers, whereas IFN-γ is released as part of an orchestrated Th1 response.
Since we want to create a Th1 response in ME/CFS, slightly higher levels of IFN-γ are desirable. Although according to Dr Chia's oxymatrine research, high levels of IL-12 in relation to IL-10 seem to be the most crucial if you are to significantly improve from taking immunomodulators.
It is very instructive to look at this the following graph from a presentation given by Dr Chia, which shows the IL-12 / IL-10 ratios of 17 ME/CFS patients taking the herbal immunomodulator oxymatrine. This ratio is indicative of the Th1 / Th2 balance.
You can see each patient's IL-12 / IL-10 ratio both before and after oxymatrine treatment. The patients who significantly improved on oxymatrine are those who sloped upwards on the graph, to a higher IL-12 / IL-10 ratio.
So this indicates an increase in the IL-12 / IL-10 ratio may be important on the route to significant improvement in ME/CFS.
(Note that there are two subtypes of IL-12, namely IL-12 p35 and IL-12 p40, but both count as IL-12).
You can hear Dr Chia talk about this above graph at timecode 37:02 in
this Dr Chia video.