For example, miR-21 is induced by tumor necrosis factor-α (TNF-α) in endothelial cells (Yang D. et al., 2018), by interleukin-1β (IL-1β) in chondrocytes (Ma et al., 2020) and by interleukin-6 (IL-6) in myeloma cells (Loffler et al., 2007). Here, TNF is linked to plasma cell myeloma.