ARHGEF15 and carcinoma: High-risk HPV types linked with malignant carcinomas, such as HPV-16, HPV-18, and HPV-31, possess a conserved E5 protein of around 80 amino acids (E5 alpha), whereas the low-risk HPV types associated with benign lesions (e.g., HPV-6 and HPV-11) contain two putative E5 proteins (E5 gamma and E5 delta), which have little sequence conservation [133].