A giant bell on a billboard in St. Louis will ring every time a child completes chemotherapy at a local hospital, per the AP. The 12-foot-tall metal bell went up Wednesday on a billboard over Interstate 44 that reads "Childhood wins another round against cancer." Hospital staff will use a mobile app to trigger the bell every time a child completes cancer treatment at St. Louis Children's Hospital, explains the St. Louis Post-Dispatch. The bell's speakers enable people passing by to hear it ring. The hospital has its own bell that children with cancer can ring to mark their last day of chemotherapy, and five to 10 kids a month do so.