Generally it's good to be skeptical but this- "We found a significant fold increase in the levels of several tumor suppressor and DNA repair gene protein products (GP)s at the end of 4th week during 4-week intermittent fasting (CALU, INTS6, KIT, CROCC, PIGR), and 1 week after 4-week intermittent fasting (CALU, CALR, IGFBP4, SEMA4B) compared with the levels before 4-week intermittent fasting."

But why would this suddenly happen?

There's some physiology here to be uncovered. That hardly is 'nothing'.

Is it calories? Is it fasting? Is it nutrient timing?

You can't find out which from "no control", but there's definitely a physiological effect being seen, correct?