Dynamic and intricate interactions between cancer cells and the tumor microenvironment sustain malignant migration and invasion. Among the peritumoral cells, cancer associated fibroblasts are relevant in breast, whereas astrocytes are noticeable in the glioblastoma context, facilitating key processes as migration and invasion. Newly developed cyclic anti-migratory and anti-invasive peptides are being tested in advanced 3D co-culture platforms using cell lines and primary cells cultured as spheroids, in biomimetic matrices and in microfluidic devices