TLR4 and familial pancreatic carcinoma: Furthermore, the release of HSP90 by cancer cells was responsible for Toll-like receptor 4 (TLR4) activation and promotion of muscle catabolism by activating p38/MAPK signaling cascade [39], consistent with previous data in pancreatic cancer, where ZIP4-mediated release of HSP70 and HSP90 promoted muscle atrophy [40].