Oncology Biomarker segmentation by Type structures a USD 18.4 billion market into five analytically distinct product classes. Protein biomarkers—comprising circulating tumor antigens, cytokines, and multiplex immunoassays—still dominate installed base revenues because they deliver rapid, cost-efficient read-outs for routine recurrence monitoring. In contrast, genetic biomarkers (somatic SNVs, amplifications, translocations) are moving fastest, catalysed by plummeting NGS costs and FDA-approval of companion diagnostics that bundle therapy with test. Epigenetic and glycomic segments occupy niches but are forecast to outgrow the field, leveraging methylation-specific PCR and high-throughput glycan arrays to capture minimal residual disease when mutational load is below sequencing detection limits. Finally, the catch-all others bucket houses emerging metabolomic and lipidomic signatures; collectively these account for <5% share today, yet patent intensity here doubled in 2023, indicating latent value for early technology licensors.