To further examine these NLS motifs, MCF-7 breast cancer cells were transfected with PKC-θ SPT mutants: SPT to EPE (which represents a constitutively phosphorylated serine/threonine) that induces nuclear translocation, and SPT to APA (which represents a constitutively non-phosphorylated serine/threonine) that blocks nuclear translocation [2,4]. Here, AGXT is linked to breast cancer.