Figure 3.

Confocal image study of 3D tumorspheres for tumor penetration evaluation after tumorspheres being incubated with a) d‐Ala‐TPApy (20 × 10⁻⁶ m) and b) d‐Ala‐TPAPy‐Clos (20 × 10⁻⁶ m). The scale bar in all the images is 50 µm.