There is provided a method for inhibiting growth and/or proliferation of a cancer cell. The method comprises treating a cancer cell with an effective amount of a polypeptide providing a cytoplasmic binding domain of a β integrin subunit for binding of ERK2 to inhibit at least one protein kinase, other than a MAP kinase, in a cell activation pathway of the cancer cell. The protein kinases inhibited by the polypeptide may be selected from the group consisting of c-Raf, MEK 1 and kinases in the Src, PI3K, PKB/AKT and PKC families. Methods for the prophylaxis and treatment of cancer are also provided.