One week after therapy, participants with very severe (i.e., WAB-AQ = 0–25) and severe (WAB-AQ = 26–50) aphasia experienced insignificant improvement by 0.20 and 2.51 PNT items (both ps > .20), respectively, while adjusting for the effects of other model terms (TPO, age, education, and WAIS/cognitive reserve). This evidence concerns the gene TPO and Aphasia.