Size exclusion study of HNP 1-3. Protein extract from tumor tissue was separated on a peptide gelfiltration column. The elution volumes of forty (unidentified) peptides was plotted against their respective mass values and an approximate elution curve was calculated. The arrows point to HNP 1-3, which were eluted in two fractions: primarily in the void volume (8 ml) together with high mass proteins (above 20 kDa) and after 14 ml together with peptides of similar mass range (2–4 kDa). We interpret this as evidence for binding between HNP 1-3 and high mass proteins.