PROS1 and Familial prostate cancer: Stimulation of prostate cancer cells with α2M* also causes transcriptional and translational upregulation of PSA synthesis [10], which is secreted and complexes with α2M. Treatment of cells with α2M-PSA complex promotes DNA and protein synthesis and upregulates RAS/MAPK and PI 3 kinase/Akt signaling pathways similar to those observed in α2M-NH2 stimulated cells [10].