RPS6KB1 and rectal cancer: Additionally, RPS6KB1 rs180515 exhibited synergistic epistasis (crude ORinteraction = 1.19) with PRKAG2 rs1104897, but RPS6KB1 rs180519 showed suppressive epistasis (crude ORinteraction = 0.80) with PIK3CA rs7640662 in rectal cancer susceptibility [73].