“…They evaluated protein–protein interactions in human embryonic kidney 293 (HEK-293) cells using protein-fragment complementation assays (PCA) to detect hidden or not expected biological functions from a wide variety of compounds, belonging to various therapeutic categories. PCA can identify unexpected anti-proliferative effects when using niclosamide, observed in various types of cancer cells, including a human prostate cancer cell (PC-3) ( Samy et al, 2020 ), a human lung cancer cell (A549) ( Özdemir, Turanli, Çalişkan, Arka, & Banoglu, 2020 ), a human pancreatic cancer cell (MiaPaCa) ( Lee, Lee, Sim, & Kim, 2020 ), a human colon cancer cell (LOVO) ( Lee et al, 2020 ), and a human glioblastoma cell (U87MG) ( Arzani et al, 2019 ), with an inhibitory concentration of 50 (IC 50 ) at the mean concentrations of 0.6 µM ( MacDonald et al, 2006 ). Since then, various preclinical studies (L. Chen et al, 2017 , Suliman et al, 2016 , Zhou et al, 2017 ) demonstrated that niclosamide exerts its anti-cancer effects through the inhibition of signaling pathways, including NOTCH, NF-κB, and mammalian target of rapamycin (mTOR).…”