Reaction channels of the BCSC niche system.

Events include self-renewal and death of BCSCs, dimerization of ligand and receptor and their dissociation, activation and inhibition of signaling molecules, and increased transcription in the presence of activating signals. Bolded reactions represent those involved in the inflammatory feedback loop between IL-6 and NF-κB. IL-6 binds to its receptor gp130, leading to Stat3 activation, which causes NF-κB activation. Activated NF-κB increases expression of IL-6, leading to a positive feedback loop, as well as increased expression of Lin-28, which activates β-catenin signaling. Let-7 directly inhibits both Lin-28 and IL-6.