CCL2 and obesity due to melanocortin 4 receptor deficiency: Thus, obesity is recognized to be a state of chronic inflammation characterized by elevated circulating levels of pro-inflammatory mediators, including IL-6, C-reactive protein (CRP), CC chemokine ligand 2 (CCL2), TNF-α, and disordered non-coding RNA, which function in the BC cell proliferation, invasion, and migration in a paracrine manner.