Following Tasse et al. (2008a) we have computed the infrared excess for the normal galaxies and for the host galaxies of X-ray selected AGN. This plot shows the difference in infrared excess between these two populations at fixed redshift and stellar mass. The X-ray selected AGN show a hot infrared excess, at short wavelengths all across the stellar mass range. For comparison we plot the infrared excess computed in a similar way for the radio selected AGN (dashed line, see Tasse et al. 2008a).