Mean oxygen abundance radial profiles derived considering galaxies in four different bins according to their integrated stellar mass. The limits of the bins were chosen to ensure a similar number of elements in each bin: log (M/M_⊙) ≤ 10.2, blue diamonds; 10.2 < log (M/M_⊙) ≤ 10.5, red squares; 10.5 < log (M/M_⊙) ≤ 10.75, yellow dots; log (M/M_⊙) ≥ 10.75, purple triangles. The symbols represent the mean oxygen abundance values, with the error bars indicating the corresponding standard deviations, for bins of 0.25 r_e. Dashed vertical lines delimit the three different behaviours in the oxygen abundance profiles (i.e. drop in the inner parts, common gradient between 0.5 and 2.0 r_e, and the flattening in the outer parts).