SF luminosity vs. quasar bolometric luminosity for the WISSH quasars in comparison with other samples. The 16 WISSH quasars are shown as blue stars in the plot, while the red asterisks show SF luminosity values reduced by a factor of about 2 to account for the quasar contribution to the FIR. The same correction has been applied to the samples from Netzer et al. (2014, 2016) and Fan et al. (2016), which are of the same luminosity range.