Test Details: Immunohistochemical testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody. Caldesmon is a cytoplasmic calcium- and calmodulin-binding protein taking part in the regulation of smooth muscle contraction. It is expressed in Smooth muscle tumours. It Is also expressed in Glomus tumours, Gatro-intestinal stromal tumours (GIST), myoepithelial tumours, inflammatory myofibroblastic tumour, epithelioid mesothelioma, etc.