Often, these studies also investigated the role of the soluble ECD after shedding, which will be discussed in Section 2.2.1, The ectodomain of L1CAM-FL engages in homotypic interactions [63] or heterotypically interacts with different binding partners such as integrins αvβ3, αvβ5 and α5β1, activated leukocyte cell adhesion molecule (ALCAM), E-selectin, neuropilin 1 and FGFR [11] in cis or trans to confer transendothelial migration, proliferation and invasion of cancer cells [23,51,63,64,66,67,68]. This evidence concerns the gene NRP1 and cancer.