It was found to be lower (HADH, CPN2, ADAM33, TDRD10, SNF1LK2, HBA2, KCNIP2, EPB42, PYGM, CEP68, ING3, EMCN, SYF2, and DTWD1) or higher (ZNF8, TOMM40, EVPL, EPN3, AP1M2, and SPINT2) in breast cancer tissue than in adjacent non-cancerous tissue (Figure 3 and Figure 4). This evidence concerns the gene SIK2 and breast cancer.