PAK1 and neoplasm: A step-wise elevation of PAK1 H-score (mean±SEM) in tumor progression: surrounding normal GEJ epithelium (4.000±0.441), atypical hyperplasia (5.200±0.509), stage I tumor (6.400±1.600), stage II tumor (8.000±0.505), and stage III tumor (9.360±0.296) (Figure 4).