STAT3 and neoplasm: IL-6, through its ability to signal via the STAT3-JAK pathway, can enhance tumor cell survival [241,242,243,244,245], promote osteoblast and tumor cell production of RANKL and PTHrP to induce osteoclastogenesis [247,248,249], induce angiogenesis [250,251,252,253], and modulate immune cell function [319].