Table 1.

A brief summary of the advantages and disadvantages of existing tumor models.

Model Type		Advantages	Disadvantages
Cell monolayer		Uses human source of cancer cells; relatively cheap costs; high throughput	Ignores the TME and its effects; cancer cell lines fail to capture phenotypic and genotypic heterogeneity
Mouse models (syngeneic models and genetically engineered mouse models (GEMM))		Recapitulates the TME; allows systemic evaluation of therapies	Very limited human relevance; difficult to control selected aspects of the TME; high costs; low throughput
Cell-line xenografts and patient-derived xenografts (PDX)		Uses human source of cancer cells; recapitulates the TME (i.e. cancer-stromal interaction)	Limited human relevance when studying cancer-immune interactions; high costs; low throughput
Engineered	Spheroid	Uses human cancer cells; recapitulates selected aspects of the TME; easily controllable; relatively cheap costs; medium throughput	Lacks the extracellular architecture; usually lacks parenchyma-stroma organization; lack clonal and genetic heterogeneity
	Organoid	Uses human cell sources; recapitulates selected aspects of the TME	Difficulty with sourcing cells
	Organotypic models	Uses human source of cells; includes parenchyma and stroma cells	Difficulty with sourcing cells and long-term maintenance
	Microfluidics	Uses human source of cells; able to control local concentrations of soluble factors; includes connectivity	Requires expert handling