IL6 and osteosarcoma: Studies by Avnet et al. showed that osteosarcoma cells co-cultured with MSCs in acidic environments boosted stemness of the osteosarcoma cells via IL-6 and IL-8 secretion, NF-κB activation, and local acidosis: reducing the pH from 7.4 to 6.8 increased resistance to doxorubicin [123].