Abstract
The original notion in quest of cancer targets to end cancer still stands, yet the secret of common human cancer was concealed by a chicken-egg paradox. Solid tumors initiate in the tumor microenvironment from rare stem cells, which express a mutant target protein as their specific marker. For decades, the stem cell and target protein cannot paradoxically be found one without first finding the other. With combined evidence from genetics, pathology, stem cell biology, clinical oncology, and herbal medicine in particular, this paradox is resolved. Historical successful anticancer herbs, together with clinical oncology drugs, paved the way to decode cancer. In solid tumors, the liable stem cells are pericyte stem cells on blood vessels in the tumor microenvironment inducing angiogenesis. One identified target protein in pericytes is a DNA repair factor and transcriptional regulator named GT198 (gene symbol PSMC3IP, alias name Hop2). Since GT198 is found as a direct drug target of many chemotherapy drugs and clinically successful anticancer herbs, more herbal medicines worldwide can now be screened against this target. In the near future, safer and more effective natural herbal medicines could systematically treat common solid tumors. This review discusses a unified theory of cancer and diseases in which pericyte stem cells are fundamental to both. It also reveals a new approach to identifying multi-functional herbs. Unlocking herbal targets in stem cells enables effective herbal identification and, in turn, awakens the herbal renaissance.