Disk-integrated line fluxes (calculated at a distance of 150 pc) of HNC as a function of disk mass (leftfor disks around T Tauri stars and right for Herbig stars). Colors represent different levels of disk flaring. Upper and lower panels are shown for different transitions. The only detection of HNC J = 1− 0 and the upper limit from stacking analysis for Lupus disks are marked for comparison. Line fluxes for TW Hya and HD 163296 are adopted from Graninger et al. (2015) and are scaled by distances.