In addition to healthy neural spheroid models, we also describe further application of two diseases including Alzheimer’s disease (AD) using iPSC-derived neurons with genetically engineered, disease-relevant alleles, as well as an opioid use disorder (OUD) neural model induced by chronic treatment with a mu(μ)-opioid receptor (MOR) agonist. This evidence concerns the gene OPRM1 and Alzheimer disease.