Due to the COVID-19 pandemic, a thorough understanding of the molecular mechanisms of cellular infection by coronaviruses has become imperative. A critical stage in cell entry by the SARS-CoV-2 virus occurs when its Spike protein mediates fusion between viral and host membranes. Recently published in the Journal of the American Chemical Society, we presented a detailed investigation of the role of selected regions of the Spike protein, and the influence of calcium and cholesterol, in this fusion process.