Kepler photometric data of the four planet-host stars. On each plot the upper panel shows the phase-folded light-curve (black dots with 1σ error bars) over-plotted with the best model (red line; see Sect. 3.2), and the lower panel shows the residuals. The models fit together the photometric data, the radial velocities, and the spectral energy distribution (Table 3 and Fig. 2). The parameters of the fits are reported in Tables 4 and 5. Only Kepler short-cadence data are plotted here for KOI-188, KOI-195, and KOI-192, but long-cadence data are also used in the analysis of these three systems. No short-cadence data are available for KOI-830, whose long-cadence data are plotted here.