Remember that prior art is not limited to patents and published materials, but includes the general knowledge that would have been available to one of ordinary skill in the field of the invention. (the-business-of-patents.com)
Would someone with ordinary skills in the field of your invention consider your invention unobvious — that is, surprising? (inc.com)
From the outset, the case has hinged on whether it was «obvious to a person of ordinary skill in the art» to do what Broad Institute researcher Feng Zhang and colleagues did with CRISPR, based on prior publications by UC Berkeley's Jennifer Doudna, working with Emmanuelle Charpentier, then of Umeå University. (sciencemag.org)