Alkalization of the tumor environment induces a reduction of exosome release. (Left) NTA analysis for the distribution and concentration of the number of exosomes released by the tumor cells cultured in pH conditions ranging from 7.4 to 6.5 (i.e., 7.4, 6.9, 6.7, and 6.5). Data are expressed as means ± SE of three independent experiments. The p-value was <0.0001 in all cellular lines cultured in acidic pH with respect to buffered conditions. (Right) NTA analysis for the distribution and concentration of the number of exosomes released by the tumor cells cultured in pH conditions ranging from 6.5 to 7.4 (i.e., 6.5, 6.7, 6.9, and 7.4). Data are expressed as means ± SE of three independent experiments. The p-value was ≤0.0001 in all cellular lines cultured in buffered conditions with respect to pH 6.5 conditions. * p < 0.1, ** p < 0.01, *** p < 0.001, **** p< 0.0001.