The dynamics of the RANKL field  are governed by production by cancer cells (rate ), diffusion (rate ), degradation (rate ) and binding to RANK receptors on active osteoclasts (rate , half-saturation ),(3)We assume that the concentration of membrane-bound RANKL is kept constant on expressing cells, and hence we neglect its decay rate, i.e. we set . Here, TNFSF11 is linked to cancer.