SCUBE2 and breast carcinoma: These cytokines selectively drive the bone-tropic metastasis of cancer cells exhibiting elevated Src activity via stimulation of the PI3K-Akt pathway, which is pivotal in regulating cellular survival and motility.204 SCUBE2, a tumor-secreted glycoprotein, is a crucial facilitator of bone metastasis in luminal breast cancer, particularly during the initial stages of niche formation.205 SCUBE2 indirectly inhibits leukocyte-associated Ig-like receptor 1 (LAIR1) signaling, impairing NK cell function and promoting tumor cell persistence and growth within the bone.