Without engaging in your point, small nitpick: These are images of Western blots[1], not PCR.
replyFrom the comments on the article by the author it looks more like 10% so far and they haven't systematically looked. That means ~10% if a probable floor of how much fraud there is.
replyNot according to the complete comment:
reply More like 10%, but my search has not been systematic. I am mostly looking where I know I will find image issues based on image filenames and “Find Similar Images” searches.