α-SMA is crucial in pathology because its expression is often altered in diseased tissues. For example, increased α-SMA expression is commonly observed in fibrotic diseases and cancer. In fibrotic diseases, myofibroblasts expressing α-SMA contribute to the excessive deposition of extracellular matrix, leading to tissue stiffness and loss of function. In cancer, α-SMA-positive myofibroblasts within the tumor microenvironment are associated with tumor progression and metastasis.
