MAP2K1 and cancer: Within the cancer PDOs, a significantly higher sensitivity of PDOs with altered versus unaltered RTK/MAPK pathway toward MEK1/2 inhibition by trametinib could be observed (Fig 6D) (AUCrel (RTK/MAPK‐unaltered): 0.7101; AUCrel (RTK/MAPK‐altered): 0.5308; two‐tailed Student's t‐test; P = 0.0356).