Gender dimorphism of Th cytokine pathways and regulation of Th cell network homeostasis are normally present in the immune response. The multivariate statistical analysis of the correlation between the levels of Th cytokines (Table 1) confirms the cytokine regulation of immune response cell phases through gender specific pathways. APC cytokines regulate the resting and activated (PHA) cell phases of immune response, through gender specific pathways: IL6 pathways is the gender specific pathways in women, but IFNγ pathways is the gender specific pathways in in men. Consequently, autoimmune disease susceptibility in women could be attributed to the influence of ΙL6, since IL6 prevents the conversion of naive Th into Treg cells in vivo, by switching Th cell differentiation from Treg to Th17, which plays a key role in autoimmune diseases. The greater probability of men developing the primary progressive form, conversely, could be the result of the influence of IFNγ on Th9 cell inhibition, since co-expression of IL-9 and IL-17 was identified as a novel Th17 function in mediating autoimmune tissue destruction, including the CNS.