p40/ Myosin

The ΔNp63 isoform, also known as p40, is the truncated or lacking the N-terminal domain and predominant isoform of p63. p40 is a nuclear protein and a transcription factor. It is confined to basal cells of squamous epithelia and urothelium, as well as basal cells/myoepithelial cells in breast, sweat gland, salivary gland, and prostate. Recent studies have shown that p40 is highly specific for squamous and basal cells and is superior to p63 for diagnosing lung squamous cell carcinoma.

Myosin is one of the major contractile proteins in muscle and non-muscle cells. It involves in conversion of chemical energy into mechanical work. A Myosin molecule consists of two heavy chains (MHCs) and two pairs of light chains. MHCs have multiple isoforms. Smooth muscle myosin heavy chain is encoded by
MYH11 gene. It is expressed in visceral and vascular smooth muscle cells as well as myoepithelial cell

Intended use

The p40 / Myosin Smooth Muscle Antibody Cocktail [BC28/SMMS-1] is a useful aid for differentiating invasive breast carcinoma from noninvasive breast lesions such as ductal carcinoma in situ (DCIS) when used with a panel of other antibodies.

Specifications
product code: 8342-C010	Clone: BC28/ SMMS-1 [Mouse monoclonals]
Staining pattern: Nuclear staining (p40)/ Cytoplasmic staining (SMMS-1)	Control tissue: Tonsil, placenta, appendix
Associated panels: Breast panel
Assessment criteria	no scan available at this time
p40: A moderate to strong, distinct nuclear staining reaction of virtually all squamous epithelial cells in tonsil Myosin: A moderate to strong and distinct cytoplasmic staining reaction of virtually all vascular smooth muscle cells in tonsil Myosin: An at least weak, distinct cytoplasmic staining of most of the follicular dendritic cells in germinal centers in tonsil
p40: An at least weak to moderate, distinct nuclear staining reaction of cytotrophoblasts must be seen in placenta
p40: No nuclear staining reaction should be seen in any cells in tonsil, except for squamous epithelial cells
Myosin: No cytoplasmic staining must be seen in epithelial cells in appendix