Briefly, DARPP-32 and its short isoform, t-DARPP, were purified from lysates of four different human lung adenocarcinoma cell lines, A549, HCC827, PC9, and H1975, using anti-FLAG M2 affinity beads and then incubated with purified IKKα protein in kinase assay buffers containing ATP. Here, CHUK is linked to lung adenocarcinoma.