SPP1 and cancer: The class of verified anti-apoptotic molecules overexpressed in cancer includes prominent tumor-associated proteins such as β-Catenin (CTNNB1) (for review see [40], [41]), Osteopontin (OPN/SPP1) (for review see [42]), BMI1 (for review see [43]), Peroxiredoxin 3 (PRDX3; [44]) and DAD1 [45].