The application dimension of the Cancer Biotherapy market is divided into four principal categories: Immunotherapy, Gene Therapy, Oncolytic Virus Therapy, and Cell Therapy. Immunotherapy—which includes checkpoint inhibitors, cytokines, and therapeutic vaccines—accounts for the largest share, driven by extensive clinical validation and broad oncology indications, contributing roughly 40% of total revenues. Gene Therapy leverages viral and non‑viral vectors to deliver corrective genetic material directly to tumor cells; its high development cost is offset by premium pricing, representing about 25% of the market. Oncolytic Virus Therapy utilizes engineered viruses that selectively replicate within malignant tissue, a niche yet rapidly expanding segment that supplies approximately 20% of sales, buoyed by recent FDA approvals. Finally, Cell Therapy, encompassing autologous and allogeneic approaches such as CAR‑T and TCR‑engineered cells, provides the remaining 15%, reflecting its emerging status and complex manufacturing pipeline. Together, these applications constitute the full scope of Cancer Biotherapy segmentation and collectively define the market’s overall size.