Distribution of photometric redshift and stellar masses (upper panel) as a function of the K magnitude for the whole BzK sample. Blue small points refer to sBzK galaxies, red dots to pBzK. In the lower panel the two dashed lines represent the nominal redshift range of the BzK distribution; in the upper panel, the green thick line represents the average M_⊙ − K relation of Daddi et al. (2004).