Very interesting how you explained this technique! The Cre/loxp system is a great method that has been used for many years and as you poninted out it is much more precise compared to newer modification methods such as CRISPR/Cas9. What do you think about its handling? I think in this regard CRISPR is advantageous. There is actually a modification of the CRISPR/Cas9 system called CRISPRi/a which does not edit the genes itself but modifies the gene regulation. I recently wrote about it, maybe you like to check it out.