Unspecific nature of the 55 kDa band is neither cell line- or species-specific.

WB analysis of human WT HEK293 and HeLa cell lysates along with murine liver tissue lysates and plasma comparing two different anti-MIC26 antibodies: A) Antibody #1 detects MIC26_22kDa and an unspecific 55 kDa protein in HEK293 and HeLa as well as in murine liver. B) Antibody #2 exclusively detects the mitochondrial MIC26_22kDa, but no 55 kDa band. C) Antibody #1 does not recognize a mitochondrial MIC26_22kDa and 55 kDa band in plasma samples from two mice. D) Antibody #2, like antibody #1, does not recognize any protein in murine plasma samples. E) Antibody #1 detects the MIC26_22kDa as well as an unspecific 55 kDa band in C2C12 cell line along with different murine tissue lysates but not plasma. F) Antibody #2 detects MIC26_22kDa in mouse cell lines and tissues but not the 55 kDa band. C2C12-A represents C2C12 cells lysed with RIPA buffer and C2C12-B represents C2C12 cells which were mechanically lysed.