Based on recent experimental studies, showing PTPRM knockdown (Im et al., 2020) or induced PTPRM methylation (Song et al., 2021) to increase STAT3 phosphorylation in cancer cells, we hypothesized PTPRM hemizygosity as a result of the interstitial 18p deletion in the triplets to cause increased STAT3 phosphorylation in immune cells. The gene discussed is STAT3; the disease is cancer.