What does this mean in lame terms? To model the sources of variation, a random intercept was speci- fied at the level of individual and gene. Fixed-effects were specified as main effects for responder (i.e. responder versus non-responder), injection-side (injected versus uninjected side), and the interaction between responder and injection-side (i.e. responder side). To facili- tate interpretation, descriptive statistics are presented in the original mRNA units using median (25th, 75th) while effect sizes are reported as the ratio of the geometric means using per cent change