SERCA, or Sarcoplasmic Reticulum Ca²⁺-ATPase, is a protein found in muscle cells that plays a crucial role in muscle contraction and relaxation. It helps transport calcium ions (Ca²⁺) from the cytoplasm back into the sarcoplasmic reticulum, a specialized organelle that stores calcium. This process is essential for muscle function, as calcium ions trigger muscle contractions. The activity of SERCA is vital for maintaining calcium homeostasis within cells. When SERCA is functioning properly, it ensures that muscles can contract and relax efficiently. Dysfunction in SERCA can lead to various muscle-related diseases and conditions, highlighting its importance in cellular health.