TLR8 and neuroblastoma: More importantly, Callaghundla et al. have shown that the “educational” process elicited by neuroblastoma cells on human monocytes through the secretion of vesicular miR-21 not only leads to a M2 polarization of the immune cells but also to a polarized monocyte-mediated TLR8 and NF-кB-dependent upregulation of miR-155 in neuroblastoma cells themselves [110].