Calcium signaling pathways are crucial for various cellular processes, including muscle contraction, neurotransmitter release, and cell growth. When a cell receives a signal, calcium ions (Ca²⁺) are released from internal stores or enter the cell from the outside. This increase in calcium concentration activates specific proteins and enzymes, leading to a cascade of cellular responses. These pathways are tightly regulated to ensure proper cellular function. Calcium can bind to proteins like calmodulin, which then modulates the activity of other proteins involved in signaling. Dysregulation of calcium signaling can lead to various diseases, including heart conditions and neurological disorders.