A Personal Scientific Journey—Looking Back at My Journey in Science: How DNA Damage and Repair Led to the Role of Gap Junctional Intercellular Communication, Mechanisms of Tumor Promotion, Human Adult Stem Cells, “Cancer Stem Cells”, Two Types of “Cancer Stem Cells” and the Modulation of Human Diseases by Epigenetic Toxins/Toxicants, Nutrition and Diets

After delivering my Keynote address to the young scientists at the International Gap Junction meeting, “International Colloquium on Gap Junctions and Cancer: Discussing how cellular communication modifies carcinogenesis and cancer treatment outcomes” (San Paulo, Brazil, 10–14 July 2023), I was asked to condense the talk into a manuscript covering the 50+ years of my scientific journey of basic biomedical research. While this journey had to omit so many important experiences, people and external events, I have tried to illustrate how my initial motivation, personal perspective of my abilities, and naïve goal as a young scientist did not prepare me for the non-linear path to where I ended. That path had many twists, turns, barriers, disappointments, surprises and wrong directions, as well as associations with co-workers, students and collaborators who afforded me with great wisdom, support and technical advice. In the history of science, few individuals have left their footprints in a straight path; however, my early education in human evolutionary genetics provided me a strong background framework, on which multiple other acquired disciplines, forced by circumstances along my uneven journey, allowed me to grow intellectually, as well as making me aware of my limitations. As my late mentor, Dr. Van Rensselaer Potter said: “… humility with responsibility”. At the completion of my experimental journey, I continued to reflect on the implied meanings of my and others’ results to view the current state of collected knowledge on global health issues as one of all scientists’ obligations, namely, to weigh the value and bioethical implications of our work to global society. “