The novel coronavirus, SARS-CoV2, can cause a potentially fatal disease, COVID-19, in humans. The infection of human cells by SARS-CoV2 includes two sequential steps: attachment of the virus to the surface receptor of target cells and the fusion of viral and host membranes. The former requires at least a receptor-binding domain on the SARS-CoV2 Spike protein that can interact with a cell surface receptor, for example, ACE2, expressed on human cells. The latter requires at least the host protease(s) to mediate proteolytic cleavage of the SARS-CoV2 Spike protein into S1 and S2 subunits and consequently promote the fusion of viral and host membranes. Also, SARS-CoV2 possesses a polybasic cleavage site that can explain the high pathogenicity of SARS-CoV2, N-glycans and O-glycans that make the dense decoration of SARS-CoV2 S protein, and cyclic regions that can interact with cell-surface GRP78. Essential elements that process SARS-CoV2 cell entry and specific characteristics that allow SARS-CoV2 to escape the immune system have the potential as targets for COVID-19 therapy.