Figure 2.

Useful scaffold-free 3D culture features in tumor metabolism study. Schematic representations of hanging drop multicellular intestinal spheroid (A); patient-derived colorectal organoid (B). Oxygen, nutrient, waste products, and growth factors gradients are indicated; color opacity and triangle width indicate high concentration. Cell types are indicated within each scheme legend. Solid arrows represent direct effects; discontinued arrows indicate indirect effects. CAFs, cancer associated fibroblasts; VEGF, vascular endothelial growth factor.