There were no associations between KRAS or GNAS mutation and tumour location (OR 0.836, 95 % CI 0.477–1.465, P = 0.532, Q = 7.624, I2 = 8.182 and OR 1.133, 95 % CI 0.785–1.634, P = 0.505, Q = 2.131, I2 = 0.000, respectively). This evidence concerns the gene KRAS and neoplasm.