Since Merkel cell carcinomas—regardless of whether they are positive or negative for Merkel cell polyomavirus—show activated PI3K/AKT signaling, PI3K and dual PI3K/mTOR inhibitors may be used as potential targeted therapies, though the literature suggests that for many tumors with pathway activation, they are not effective as single agents [24, 25]. The gene discussed is PIK3CA; the disease is Merkel cell skin cancer.