PPA1 and lung cancer: In lung cancer, lesions greater than 5 cm (n = 61) exhibited stronger expression of PPA1 than those less than or equal to 5 cm (n = 124; P = 0.018); patients aged less than 60 years (n = 105) exhibited stronger expression of PPA1 than those 60 years of age and older (n = 77; P = 0.004).