An assessment of extracellular Hsp70 concentrations normalized to 1 × 106 viable tumor cells showed significantly increased values on days 4 and 7 after an irradiation with 4 and 6 Gy compared to sham irradiated cells (p ≤ 0.05), whereas on day 1 no significant increase in extracellular Hsp70 in the cell culture supernatant was detected (Figure 5C). Here, HSPA1A is linked to neoplasm.