SMAD4 and cancer: The L-S4 tumours also had higher βA-subunit (621.2; IQR: 433.9–701.6 vs. 340.2; IQR: 287.6–442.4) and FS (688.4; IQR: 479.9–773.3 vs. 237.4; IQR: 287.6–631) alongside lower βB-subunit (61.4; IQR: 42.7–82.3 vs. 99.03; IQR: 83.4–118.1) proteins relative to cancers with normal Smad4 (p < 0.0001 for all).