IL6 and neoplasm: On the other hand, anti‐mouse IL‐6R antibody given by i.p. injection twice a week from day 7 to day 21 after inoculation, did not inhibit tumor growth in the N‐inv model (rat IgG [control] vs. anti‐mouse IL‐6 antibody [mean ± SD], 0.865 ± 0.623 g vs. 1.561 ± 0.755 g; p = 0.173).