In particular, mortalin represents a promising drug target candidate based on the selective expression of mortalin/client protein complexes in cancer cells and the minimal-to-no toxicity of mortalin-inhibitory drugs on healthy cells and in animal models (Deocaris et al., 2009; Lu et al., 2011; Kabirov et al., 2012; Garg et al., 2020; Sari et al., 2021). Here, HSPA9 is linked to cancer.