Analysis of ubiquitin ligase 3A (UBE3A) and GABA
receptor β3 (GABRB3) protein levels in postmortem human brain samples. Box-and-whisker plots diagramming protein levels in postmortem human brain tissue normalized to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) by Western blot analysis with a significant increase of UBE3A protein level in duplication of 15q11-q13 (dup15q) (a) and no significant change in GABRB3 protein levels (b). Significant differences are indicated by *P < 0.05 and **P < 0.01. Significant differences in the group means were determined by t-test. Distribution histograms of protein levels of individual brain tissue samples are shown in Additional file 7.