IGF-IIR also known as M6P-R, IGF2R is a receptor for both insulin-like growth factor 2 and mannose 6-phosphate. IGF-IIR plays a significant role in cellular processes. IGF-IIR is primarily located in the cell membrane, where IGF-IIR functions as a receptor that binds glycoproteins through extracytoplasmic domains. This binding is essential for mediating the activation of transforming growth factor beta 1 (TGFβ1), which acts as a growth inhibitor, as well as for the degradation of insulin-like growth factor II (IGF-II) and the transport of lysosomal enzymes. IGF-IIR′s ability to form oligomeric complexes enhances affinity for lysosomal enzymes, thereby facilitating their transport and function. Unlike IGF-IR, IGF-IIR does not promote the signaling pathways associated with IGF-I or IGF-II, which are known for their mitogenic and cell survival effects, thus positioning IGF-IIR as a tumor suppressor.