Upper panels: HNC 3−2 emission for TW Hya from ALMA observations and the deprojected azimuthally averaged (normalized) radial intensity profile for HNC emission in TW Hya (purple line). A model profile convolved with the same beam size as the ALMA observations is also shown for comparison (gray line). Lower panels: moment-zero maps for the HNC 1− 0 detection of J160830.7-382 827 and stacking results for the remaining 28 disks in the Lupus sample from ALMA observations. White contours depict the continuum emission for the transition disk J160830.7-382 827, where dust emission is absent in the disk center, while HNC 1− 0 emission mostly originates within the dust hole. The beam sizes are shown in the left corner of each panel.