Multiple clonal forebrain tumours, originating invariably at the ependymal layer were found in all LATS1/2 cKOs, but not in controls or individual LATS1 cKOs or LATS2 cKO at P20 (18/18 dual knockout, 0/3 LATS1 cKO, 0/3 LATS2 cKO, 0/6 controls), indicating redundancy between LATS1 and LATS2. The gene discussed is LATS2; the disease is neoplasm.