STK11 and lung adenocarcinoma: For example, in 230 cases of lung adenocarcinoma studied by The Cancer Genome Atlas (TCGA) network [163], the PRKAA1 gene was amplified in 22 (10%), while the STK11 gene (encoding the upstream kinase LKB1) was subject to either deletions, or mutations expected to cause loss-of-function, in 43 (19%).