However, according to our previous study, serum IL-6 levels were not different between the FSL and FRL.44 The let-7 family was previously shown to directly inhibit IL-6 expression in breast cancer cell lines, to be abundant in the adult brain and to be implicated in the regulation of neural stem cell proliferation, differentiation and synaptic plasticity.22, 23, 24, 25, 26 We showed that the Il6 elevation in PFC of FSL was associated with a reduced let-7 miRNAs expression. The gene discussed is IL6; the disease is breast cancer.