May be an activator of G protein signaling. Almost absent from healthy skin; especially in epidermal keratinocytes, skin fibroblasts or endothelial cells and is barely detectable in benign melanocytic naevi. Expressed in the stroma close to skin tumors, in the tumor cells themselves and in the epidermis of psoriasis. By TGFB1 present in the melanoma cell conditioned medium (MCCM). It is uncertain whether Met-1 or Met-53 is the initiator. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus.