SPP1 and thyroid tumor: NF-κB signaling cascade activation is another pathway reported to be associated with OPN expression in thyroid tumors, once follicular thyroid cancer displaying high OPN expression also exhibited high levels of the p65 NF-κB subunit [83], while, in papillary thyroid cancer, the overexpression of NF-κB increased SPP1 expression, which was modulated by the HGMA1b and CBX7 proteins [78].