The invention relates to the use of an anti-CK8 antibody alone or in combination therapy (with another antibody and/or chemotherapeutic agent) to (1) treat solid tumours expressing CK8 having wild-type K-Ras (not mutated as disclosed herein) and (2) treat solid tumours expressing CK8 having K-Ras mutation as disclosed herein. The invention also relates to the use of anti-CK8 antibodies having internalizing property, allowing to deliver cytotoxic agent coupled to antibody for the treatment of CK8 positive solid tumours, having wild-type K-Ras (not mutated as disclosed herein) or having K-Ras mutation as disclosed herein.