Slides of 22 endoscopically resected T1CRCs, which included cases from both the sequencing and validation cohorts, were stained for cathepsin H. Immunohistochemistry revealed high expression levels of cathepsin H in stroma-rich regions in the invasive part of the tumor, and in particular in fibroblast-like, spindle-shaped cells (Figure 15A). The gene discussed is CTSH; the disease is neoplasm.