Stimulus-triggered acquisition of pluripotency first came to the public's attention on Jan. 28, after the British journal Nature published research showing that Haruko Obokata and her team in Kobe had successfully reprogrammed the mature cells of mice into STAP cells by subjecting them to stress — specially, submersing them in a mildly acidic liquid. Obokata's methodology has since been questioned but if ever proven valid, STAP would be a radically simpler method of stem-cell generation, as it does not require nuclear transfer or the introduction of transcription factors.