IFNG and infection: As shown for natural infection, donors with a detectable CD8+ T cell response displayed a lower proportion of CD8+ T cells with measurable cytokine production (IFNγ: 4/5 [80%] in MM patients vs. 6/6 [100%] in HCs, p = 0.2506; TNF: 4/5 [80%] in MM patients vs. 6/6 [100%] in HCs, p = 0.2506) and degranulation (CD107a: 3/5 [60%] in MM patients vs. 6/6 [100%] in HCs, p = 0.0868) (Figure 3E).