Upon binding to αvβ3, OPN can promote cell motility and tumor progression through nuclear factor-inducing kinase (NIK)–ERK (extracellular signal-related kinase) and MEKK1 (mitogen-activated protein kinase kinase kinase1)–JNK1 (c-Jun N-terminal kinase 1) signaling pathways to active AP1 [13]. Here, SPP1 is linked to neoplasm.