TPI1 and lung carcinoma: They found that loss of LKB1 in KRAS and TP53 co-mutant human lung cancer cells decreased phosphorylation of TPI1 (Triosephosphate isomerase 1), a metabolic enzyme that catalyze the interconversion between glyceraldehyde-3-phosphate (GA3P) and dihydroxy-acetone phosphate (DHAP), at serine 21 through SIK (Figure 3).