Interestingly, an interaction between ERK and VDR signaling pathways has previously been proposed: in MG-63 (human osteoblastic osteosarcoma cell line) and HeLa (human cervical carcinoma cell line) cells, ERK activation leads to increased VDR transcriptional activity through overexpression of its coreceptor RXR gamma [44]. The gene discussed is VDR; the disease is osteosarcoma.