It would not be out of context to mention at this point that at tumor initiating conditions, expression of IFNγ, a key Th1 response cytokine [62] was suppressed when anti-CD3/anti-CD28-treated CD4+ T cells were exposed to CM of MDA-MB-468 CSC (CSC: T cell ratio 1:5) in comparison to unexposed anti-CD3/anti-CD28-treated CD4+ T cells (p < 0.01) (Online Resource 5, Supplementary Fig. 3). This evidence concerns the gene CD28 and neoplasm.