Activation of MAP kinases (ERK, JNK) has been shown to be an important consequence of CIS overexpression in CD4 T cells (Li et al, 2000), and is thought to be a result of direct association between CIS and PKC theta, since this PKC is able to activate MAP kinases (Baier-Bitterlich et al, 1996). Here, CD4 is linked to in situ carcinoma.