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| | Ras |
 | | A high incidence of ras gene mutations has been reported in malignant tumors of the pancreas (80-90%, K-ras) (2, 24), in colorectal carcinomas (30-60%, K-ras) (5, 26), in non-melanoma skin cancer (30-50%, H-ras) (4, 21), in hematopoietic neoplasia of myeloid origin (18-30%, K-and N-ras) (5, 16, 17, 22), and in seminoma (25-40%, K-ras) (15, 19). |
 | | RAS proteins are localized in the inner plasma membrane, bind GDP and GTP and possess an intrinsic GTPase activity, implicated in the regulation of their activity. |
 | | Ras genes are expressed in all tissues, have a promotor region with multiple GC boxes, but lack a TATA- or CCAT-box; features resembling the promotors of housekeeping genes (11). |
| www.infobiogen.fr /services/chromcancer/Deep/ras.html (4180 words) |
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