However, despite the promising prognostic capabilities of MALDI-MSI in BC, only eight signals could be identified by MS2, namely the histone H2AC1, cytokeratins KRT19 and KRT7, hemoglobin, collagen-I alpha chain, and HSPB1 (heat-shock protein beta-1), which was a limitation of this intriguing study because none of the signals could be ascribed to recurrence/progression, with the sole exception of the signal at m/z = 2705.8, corresponding to a peptide from the collagen-I alpha chain. Here, HSPB1 is linked to breast cancer.