SMAD4 and metastatic neoplasm: The Cdkn2a/b deletions were highly concordant between primary and metastatic tumors (Extended Data Fig. 1e) and they mirrored the genetic association of SMAD4 alterations with homozygous CDKN2A/B deletions in the MSK-IMPACT cohort of human PDAC (Extended Data Fig. 1f).