Despite their benefits, PDX models have certain limitations: - High Cost and Time-Consuming: Establishing and maintaining PDX models is expensive and labor-intensive. - Limited Immune System: Since PDX models use immunodeficient mice, they do not fully replicate the human immune response, which is crucial for understanding immunotherapies. - Engraftment Rates: Not all patient tumors successfully engraft in mice, and some tumor types have low engraftment rates.
