Therefore, we aim to investigate: (a) whether BARHL1 expression is associated with neurodegenerative diseases like AD, Parkinson’s disease (PD) or amyotrophic lateral sclerosis (ALS); (b) if there is any relationship between BARHL1 expression and hormone-induced tumor of the breast; i.e., estrogen-positive breast carcinomas, HER2-positive and triple negative breast carcinomas being included as controls; and (c) an in-depth bioinformatics analysis to demonstrate a probable role of BARHL1 in AD patho-physiology and the molecules possibly associated with this regulation. The gene discussed is ERBB2; the disease is Parkinson disease.