HEK293T cells were transfected with the pCMV6-ENTRY control (Cat# PS100001, Left lane) or pCMV6-ENTRY SPR (Cat# RC205679, Right lane) cDNA for 48 hrs and lysed. Equivalent amounts of cell lysates (5 ug per lane) were separated by SDS-PAGE and immunoblotted with anti-SPR antibody (Cat# TA501963). Positive lysates [LY401086] (100 ug) and [LC401086] (20 ug) can be purchased separately from OriGene.