Moreover, a newly identified member, known as neurotrophic factor alpha 1 (NF-α1) or carboxypeptidase E has recently garnered attention due to its neuroprotective (Cheng et al., 2013), neurogenesis-promoting (Cheng et al., 2015), and dementia, AD and depression attenuating potential (Cheng et al., 2015, 2016; Xiao et al., 2023). Here, CPE is linked to Alzheimer disease.