PMS2

And here's a summary of the biomarkers she had tested.

The typical MMR evaluation, MLH1, PMS2.

MSH6, MSH2.

When there's loss of expression, that means there's an abnormality.

Surgery and pathology confirmed that it was recurrent colorectal cancer.

Immunohistochemistry staining showed loss of MLH1 and PMS2, which suggested a mismatched repair deficiency.

This was our first important clue.

Then we ran a CGP on the tissue that identified a deleterious POLD1 alteration.