Over the last fifty years, interdisciplinary approaches in biology have become popular with the emergence of fields such as systems biology and biophysics. Mathematical modelling and the use of quantitative approaches have been successful in shedding light into the emergent behavior of cells and tissues. However, despite great advances in molecular cell biology and genetics, we are still far from building predictive models describing the self-organization of living systems. One of the main drawbacks is the poor connection between microscopic and mesoscopic descriptions, a well-known problem in physics. In this talk, I will propose the use of techniques borrowed from soft matter physics to bridge scales in biological systems, thus unveiling how mesoscopic quantities depend on microscopic quantities such as kinetic parameters. In particular, I will focus on the role of solid-to-fluid transitions at the subcellular and supracellular scales and show how multiscale modelling will be key in the future to build predictive theories in biology.