They hypothesized that a prolonged stimulation of principal cell proliferation by lithium, via its inhibition of the enzyme glycogen synthase kinase 3 beta and the increased availability of β-catenin in tubular cells (Kjaersgaard et al. 2012; Nielsen et al. 2008; Saadi-Kheddouci et al. 2001) can eventually induce adenomas and carcinomas. Here, GSK3B is linked to carcinoma.