HSPA1A and lung cancer: In the case of H1299 lung cancer cells, ectopic expression of MDM2 released HSPA1A/HSP70 and DNAJB1/HSP40 from the p53 R175H-TAp73α complex in a dose dependent manner, thus leading to the formation of p53 R175H-TAp73α-MDM2 complex (Figure 4A).