NCAM1 and cancer: Our unsorted scRNA-seq strategy enabled cell–cell communication analysis between the tumor and TME in the BM of MM patients, revealing that the tumor cell populations might be the major source of cancer-related signals involving NCAM, MPZ, GAS6, ALCAM, BAG, and CCL. GAS6, which encodes the GAS ligand, is overexpressed in many cancers and promotes cancer cell proliferation and survival44.