CTLA4 and neoplasm: By contrast, complete regression of tumour growth was seen in 62% of subjects when large (greater than 1200 mm−3) Neuro2A tumours were treated with higher rarefactional pressure exposures (P− = 14 MPa, f = 1.5 MHz, 13.3 ms long pulses) in combination with anti-CTLA-4/PD-1 antibodies and was associated with the induction of systemic immunity including the pro-immune regulation of natural killer cells, CD11c+ cells and circulating cytokines [18].