PIK3CA and cancer: Most commonly over-expressed genes in 3q26 amplified cases include PIK3CA, TBL1XR1, DCUN1D1, and less commonly SOX2 and PRKCI. Conclusion: The subset of squamous cervical carcinomas with 3q26 amplifications is not overlapping with cancers carrying PIK3CA mutations and contains, besides PIK3CA, other cancer-associated genes that are over-expressed at the mRNA level, including TBL1XR1 and DCUN1D1. DCUN1D1, a regulator of SCF ubiquitin ligase activity, may be a relevant pathogenic player given the importance of ubiquitination and the proteasome in the disease.