It costs nothing to say "lab testing" instead of "in vitro". Literally the same number of syllables, zero loss of precision, and immediately understandable to a wider audience.
Testing in mice is considered lab testing though, so clearly something is getting lost in translation, no? All you really need to know to infer from context is "vivo" = "alive" and "vitro" = "glass".
It costs nothing to say "lab testing" instead of "in vitro". Literally the same number of syllables, zero loss of precision, and immediately understandable to a wider audience.