In search of a molecular mechanism of how the accumulation of these two key oncoproteins could stimulate the acquisition of chemoresistance, we show that heat shock proteins (DNAJB1/HSP40 and HSPA1A/HSP70), apart from stabilizing mut p53, are also involved in the mut p53-TAp73α interaction in breast and lung cancer cells. The gene discussed is HSPA1A; the disease is lung cancer.