IL6 and myalgic encephalomeyelitis/chronic fatigue syndrome: For LR04 CFS, all the 20% concentrations did not reduce IL-6 production upon infection, except for the TIL-produced CFS + vitamin D (p < 0.01 vs. infection control; Figure 4d), which was more effective than TIL-CFS alone (p < 0.0001) and better than the same condition in MRS (p < 0.001).