SPP1 and lung cancer: To identify the molecular mechanism and downstream pathways by which SQS regulates lung cancer cell progression, we analyzed the GSE37868 (as an mRNA microarray of CL1-0/SQS compared with CL1-0/Vector) datasets7, and secreted phosphoprotein 1 (SPP1; also known as osteopontin, OPN) was the top-ranking downstream factor that was upregulated upon SQS overexpression in CL1-0 cells.