After binding with their receptors, these interleukins and growth factors trigger in tumor cells the activation of signaling pathways such as the JAK2/STAT3, PI3K/AKT, RAS and the downstream mitogen-activated protein kinase (MAPKs), which provoke not only tumor growth and survival but also drug resistance, migration, and dissemination of myeloma cells [72,73]. Here, STAT3 is linked to neoplasm.