It is a limitation that the C4G and PRO-C3 biomarkers have not been assessed in tumor samples, e.g., with microscopy, and it could be valuable to correlate the serological biomarker levels of PRO-C3 and C4G, and PRO-C3 and C4G staining, with tumor measurements of collagen density and T-cell infiltration. Here, C3 is linked to neoplasm.