A process for purifying a sample of h38C2 antibody or variant thereof, wherein both antigen binding sites are fully available for antigen binding in at least about 85% of the antibodies in the sample, comprising (i) Equilibrating a HIC (Hydrophobic Interaction Chromatography) column with a pre-loading equilibration wash comprising a base buffer that comprises between about 15mM and about 100mM sodium phosphate, potassium phosphate or ammonium phosphate HEPES, Tris and bis-Tris, at between about pH6.5 to about 7.5, and further comprises a salt selected from the group consisting of NaCl, KCl, and monosodium citrate, at a first concentration of between about 0.5M and 1.5M; wherein the HIC column comprises phenyl conjugated resin beads below about 50μm in diameter and comprising pores of at least about 500A; (ii) Loading the column with a sample of h38C2 at between about 4 and about 80g/L in loading buffer comprising the base buffer and further comprising the salt at the first concentration; (iii) Washing the column with post-loading equilibration wash comprising the base buffer and the salt at the first concentration; (iv) Washing the column with a salt gradient, comprising the base buffer and further comprising a linear concentration gradient from about 1.5M to about 0.25M of the salt, characterised in that the salt concentration decreases by between about 90mM and 100mM per column volume (v) Washing the column with a salt plateau wash, comprising between about 4CV and about 8CV of the salt at between about 0.25M and about 0.4M in the base buffer; (vi) Washing the column with a buffer wash comprising the base buffer; (vii) Eluting the h38C2 with an elution buffer, comprising the base buffer and a linear concentration gradient of 1,6 hexanediol beginning at a concentration of between about 0 to about 1 % of 1,6 hexanediol and ending at an upper limit selected from the group consisting of about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 21 %, and about 22% of 1,6 hexanediol for between about 0.5CV to about 3CV or until the elution pool is collected. (viii) Optionally running a further elution step comprising the base buffer and 1,6 hexanediol at a concentration selected from the group consisting of about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 21%, and about 22%, for up to 5CV or until the elution pool is collected; wherein the h38C2 antibody or variant thereof comprises a light chain variable region (V L) comprising a V L CDR1, V L CDR2, and V L CDR3 of the V L sequence shown in SEQ ID NO:27; and preferably as set forth in SEQ ID NO:27, and a heavy chain variable region (V H) comprising a V H CDR1, V H CDR2, and V H CDR3 of the V H sequence shown in SEQ ID NO:28, and preferably as set forth in SEQ ID NO:28. (i) Equilibrating a HIC (Hydrophobic Interaction Chromatography) column with a pre-loading equilibration wash comprising a base buffer that comprises between about 15mM and about 100mM sodium phosphate, potassium phosphate or ammonium phosphate HEPES, Tris and bis-Tris, at between about pH6.5 to about 7.5, and further comprises a salt selected from the group consisting of NaCl, KCl, and monosodium citrate, at a first concentration of between about 0.5M and 1.5M; wherein the HIC column comprises phenyl conjugated resin beads below about 50μm in diameter and comprising pores of at least about 500A; (ii) Loading the column with a sample of h38C2 at between about 4 and about 80g/L in loading buffer comprising the base buffer and further comprising the salt at the first concentration; (iii) Washing the column with post-loading equilibration wash comprising the base buffer and the salt at the first concentration; (iv) Washing the column with a salt gradient, comprising the base buffer and further comprising a linear concentration gradient from about 1.5M to about 0.25M of the salt, characterised in that the salt concentration decreases by between about 90mM and 100mM per column volume (v) Washing the column with a salt plateau wash, comprising between about 4CV and about 8CV of the salt at between about 0.25M and about 0.4M in the base buffer; (vi) Washing the column with a buffer wash comprising the base buffer; (vii) Eluting the h38C2 with an elution buffer, comprising the base buffer and a linear concentration gradient of 1,6 hexanediol beginning at a concentration of between about 0 to about 1 % of 1,6 hexanediol and ending at an upper limit selected from the group consisting of about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 21 %, and about 22% of 1,6 hexanediol for between about 0.5CV to about 3CV or until the elution pool is collected. (viii) Optionally running a further elution step comprising the base buffer and 1,6 hexanediol at a concentration selected from the group consisting of about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 21%, and about 22%, for up to 5CV or until the elution pool is collected;