Given that lysosome activity is tightly linked to autophagy (Sui et al, 2013) and previous studies reported the induction of autophagy by HSP90 inhibitors in cancer (Liu et al, 2012; Samarasinghe et al, 2014; Mori et al, 2015; He et al, 2016; Zhao et al, 2019), we decided to explore this process as a potential actionable resistance mechanism to HSP90 inhibition in brain metastasis. Here, HSP90AA1 is linked to cancer.