Drug repositioning pipeline overview. Schematic representation of drug repositioning pipeline for squamous cell carcinoma (SCC). First, cancer-related proteins and drugs were extracted from PharmDB using cancer terms (such as “Carcinoma”, “Neoplasm”, and “Cancer”). Second, inferred SCC-related drugs were extracted using the shared neighborhood scoring algorithm. Among the candidates, any known cancer agents were filtered out; leaving only drugs that had not been previously implicated as anti-cancer drugs. Then the FDA approved drugs which known to be related with cancer-related proteins were maintained for further analysis as SCC drug candidates in this study.