Lopinavir is an HIV protease inhibitor that displays antiviral and anticancer activities. In vitro, lopinavir inhibits sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), decreasing intracellular Ca2+ levels. In vivo, lopinavir’s inhibition of SERCA induces endoplasmic reticulum stress. In human papilloma virus (HPV)-positive cervical cancer cells, lopinavir upregulates ribonuclease L protein (RNASEL), potentially inducing cell death. In meningioma cells, lopinavir induces cell cycle arrest and inhibits cell growth.