Fig. 2. Mutational prevalence, mutational signature, and genomic rearrangement of gastric cancer PDX.

a Bar plot of PDX mutation prevalence ranked from the left to the right by increasing mutation counts per megabase. Histogram of proportions of nucleotide transversions, transitions, and indels in the corresponding PDX with indication of the molecular subtypes following the TCGA and ACRG classification. mRNA expression and mutation status of MLH1 (qRT-PCR data and whole exome sequencing data, respectively) and others mismatch repair genes (MSH2, MSH3, MSH6, PMS2, POLE; for these genes loss of mRNA expression was determined by Affymetrix HGU133 Plus 2.0 analysis) in the 27 PDX with indication of the mutation types. b MLH1 protein detection performed by immunohistochemistry for the 27 PDX. Tumors were categorized as MSI in case of absence of a homogeneous MLH1 chromatin staining.