“…Continuum models such as single-phase and multiphase mixture models treat tumors as a collection of cells at larger scales and principles from continuum mechanics such as mass and momentum conservation are used to construct partial differential equations and integro-differential equations governing the motion of cell densities, or volume fractions, stresses and cell velocities. See, for example, the recent reviews (Ribba et al, 2004; Quaranta et al, 2005; Hatzikirou et al, 2005; Nagy, 2005; Wodarz et al, 2005; Byrne et al, 2006; Fasano et al, 2006; van Leeuwen et al, 2007; Roose et al, 2007; Graziano et al, 2007; Harpold et al, 2007; Drasdo and H ö hme, 2007; Friedman et al, 2007; Sanga et al, 2007; Anderson and Quaranta, 2008; Bellomo et al, 2008; Cristini et al, 2008; Deisboeck et al, 2009; Byrne, 2010; Rejniak and McCawley, 2010; Lowengrub et al, 2010; Deisboeck et al, 2011; Frieboes et al, 2011; Kim et al, 2011; Kam et al, 2012; Hatzikirou et al, 2012; Szab ó et al, 2013; Baldock et al, 2013; Katira et al, 2013) for a collection of recent results.…”