A number of studies have reported transcriptome-wide sex differences in AD including genes that suggested activation of the immune system which were increased in male and female AD patients although the greater number of dysregulated genes, for example CHI3L1 (Sanfilippo et al., 2019), was markedly increased in samples from females (Paranjpe et al., 2021). This evidence concerns the gene CHI3L1 and Alzheimer disease.