GLS2 and cancer: On the other hand, the GA band presented in nuclear fractions isolated from human cancer cell lines cannot be ascribed to GLS isoforms by two main reasons: first, we always use affinity-purified isoenzyme-specific antibodies for cell immunostaining and Western blots, which only recognize GLS or GLS2 isoforms, but not both of them24,25 (Figs. S9 and S10); second, neither KGA nor mitochondrial contamination, that might give rise to a GLS band, were present in nuclear extracts employed in the analysis.