By analyzing LC–MS/MS ranking data (Fig. 2G) for proteins associated with GBM aggressiveness, we identified CD44 as a proof-of-concept candidate with consistently high rankings (ranked 2/2 (surface/endocytosed; U3034MG), 5/23 (U3047MG), and 28/46 (U3017MG)). Here, CD44 is linked to glioblastoma.