Table 1.

Advances in modeling colorectal cancer.

Model	Application	Advantages	Disadvantages
2D In vitro	• Adhesion • Gene expression • Drug screening	• Simple • Low cost • High throughput	• Low predictive power • Lack of native architecture • Loss of tumor heterogeneity
Culture plate
Wound healing	• Migration
3D In vitro	• Proliferation • Migration • Gene expression • Drug screening	• Retain native tumor geometry • Cell-cell/ECM interaction • Tumor heterogeneity	• Avascular • High cost • Low scalability • Low reproducibility
Organoid/  Spheroid
Co-culture	• Stromal crosstalk • Immune crosstalk
In vivo  Patient-derived xenografts	• Proliferation • Migration • Invasion • Angiogenesis • Gene expression • Drug screening	• Tumor heterogeneity	• High cost • Laborious • Low predictive power • Immunocompromised • Limited metastasis
Humanized mice		• Tumor microenvironment • Tumor heterogeneity • Immunocompetent	• High cost • Laborious • Incomplete immune function • Engraftment difficulties
Genetically engineered mice		• Tumor microenvironment • Tumor heterogeneity • Immunocompetent • Natural disease progression	• High cost • Laborious • Time consuming
Organ-on-a-chip	• Proliferation Migration • Intravasation Extravasation • Invasion • Angiogenesis • Stromal crosstalk • Immune crosstalk • Gene expression • Drug screening	• Tumor microenvironment • Tumor heterogeneity • Vascular • Hydrodynamic properties • Biochemical gradient • Precise control • Easy visualization	• Lack of standardization • High cost • Laborious • Low reproducibility