The stellar mass vs. size relation for massive red-sequence early-type galaxies in the core of XMMU J2235. Filled symbols are spectroscopic members, empty symbols are sources with photo-z within 3σ of the cluster redshift. The black line and shaded area show the Shen et al. (2003) determination of the local stellar mass vs. size relation and its scatter (1σ), based on a sample of SDSS early-types. The dotted line shows the Shen et al. (2003) relation shifted by a factor 2 in size. The gray line with errorbars shows the local mass vs. size relation determined by Valentinuzzi et al. (2010) for a sample of nearby cluster galaxies.