In the cellular biology, stress granules are biomolecular condensates in the cytosol composed of proteins and RNA that assemble into 0.1–2 μm membraneless organelles when the cell is under stress.[1][2] The mRNA molecules found in stress granules are stalled translation pre-initiation complexes associated with 40S ribosomal subunits, translation initiation factors, poly(A)+ mRNA and RNA-binding proteins (RBPs). While they are membraneless organelles, stress granules have been proposed to be associated with the endoplasmatic reticulum.[3] There are also nuclear stress granules. This article is about the cytosolic variety.