Cellular localization refers to the specific location of molecules, such as proteins and RNA, within a cell. This positioning is crucial for cellular function, as it determines how these molecules interact with each other and participate in various biological processes. Different cellular compartments, like the nucleus, mitochondria, and cytoplasm, provide distinct environments that influence molecular behavior. Understanding cellular localization helps researchers identify how diseases develop and how treatments can be targeted. For example, mislocalized proteins can lead to conditions like cancer or neurodegenerative diseases. Techniques such as fluorescence microscopy are often used to visualize and study these localizations in living cells.