WEE1 and neoplasm: To further investigate the changes in GSK3 protein kinase activity, western blotting was used to analyse a subset of Group 1 tumours (03, 13, 17, 23 and 27) (Fig. 5A) for the phosphorylation of GS and two additional established GSK3 substrates: the p65-RelA subunit of NFκB on S468 [30] and CRMP on T514 [31].