One nonexclusive aspect provides molecules further improved from antibodies that can bind to antigens in an ion concentration-dependent manner. An alternative nonexclusive aspect provides safe and more advantageous Fc region variants that have decreased binding to pre-existing ADA. An alternative nonexclusive aspect provides novel IL-8 antibodies that are superior as pharmaceuticals.本發明之一非排他的態樣提供一種分子,其係從能以離子濃度依賴方式結合於抗原的抗體改進而得。另一非排他的態樣提供安全及更有利的Fc區變體,其對於預先存在的ADA的結合降低。另一非排他的態樣提供新穎的IL-8抗體,其作為藥物係優越的。