Fibroblast activation protein α (FAPα), a membrane‐anchored type II transmembrane serine protease,[20] is highly overexpressed in more than 90% of epithelial tumors, whereas its expression is significantly lower in normal human tissues.[21] FAPα has been implicated in tumor growth, metastasis, the promotion of extracellular matrix degradation, and cellular invasiveness during tumor progression.[22] Therefore, it could be regarded as a promising biomarker for cSCC diagnosis. Here, FAP is linked to neoplasm.