Tumor protein p63 antibody, also known as transformation-related protein 63 is a protein that in humans is encoded by the TP63 gene. Many studies have shown that p63 is a sensitive (90%) and fairly specific marker for squamous cell carcinoma and may be used in distinguishing poorly differentiated squamous cell carcinomas from adenocarcinomas. p63 has been shown to mark approximately 5 to 10% of lung adenocarcinomas.
Tripartite motif-containing 29 (TRIM29) is a relatively new marker. A comprehensive study has shown that TRIM29 is a sensitive marker (93.7%) for lung squamous cell carcinoma (SqCC) and is a fairly specific marker staining only 6.1% of lung adenocarcinomas.
p63 is a nuclear stain that marks lung SqCC (DAB), and TRIM29 is a cytoplasmic/membrane stain that also marks lung SqCC (Fast Red). In most cases, a co-expression of both antibodies will be observed in lung SqCC. Studies have also shown that when p63 and/or TRIM29 is expressed in lung SqCC, a 95.4% sensitivity and 100% specificity was achieved, if Napsin A and TTF-1 were both negative in the same case. Therefore, the antibody combination of p63 + TRIM29 is an excellent screener for discriminating lung SqCC vs. lung adenocarcinoma.