HSPA1A and cancer: After 24, 48, and 72 hours, significantly upregulated HSP70 1A [HSPA1A] mRNA expression levels were observed in 5-FU–treated cancer cells at all investigated temperatures (37°C: FD 2.2, FD 2.9, and FD 2.5; 41°C: FD 1.9, FD 3.0, and FD 1.9; 43°C: FD 2.1, FD 3.7, and FD 3.7, respectively) (Figure 4A, top).