The significant down-regulated overlapping genes are as follows: (a) ST6GALNAC5 and RIMS1 among T2D, AD, and MS, (b) ZBTB7A and YME1L1 among T2D, ALS, and ED, (c) FUT6 among T2D, AD, and ALS, (d) BRF1 among T2D, ALS, and CP, (e) CDC14B among T2D, ALS, ED, and MS, (f) CD47 among T2D, ALS, HD, and ED, (g) NRG1 among T2D, ALS, HD, and MS, (h) DNM1 among T2D, CP, and MS, (i) TLB1XR1 among T2D, HD, and MS, and (j) GPR161 among T2D, ALS, and MS. This evidence concerns the gene NRG1 and Alzheimer disease.