SMAD4 and neoplasm: To build a set of matched PDX and tumor organoid models, we identified 8 PDX models that have heterogeneous combination of alterations in the common pancreatic cancer oncogenes, such as KRAS, TP53, CDKN2A, SMAD4, c-MYC, GATA6, ERBB2, as well as other genetic alterations in SWI/SNF, DNA damage repair, and axon guidance pathways (15–17) as determined by exome sequencing analysis of the PDX tumors (Figure 1A).