PTH and plasma cell myeloma: Wang et al. (2011) accounts for IL-6 stimulation of multiple myeloma cells and IL-6 activation of RANKL. Wang et al. (2011) also performs a perturbation analysis to investigate the relative degree of RANKL activation by PTH versus IL-6 in homeostatic and diseased remodeling states and finds that PTH dominates over IL-6 under healthy bone remodeling conditions.