1. The use of a CHK1 inhibitor in combination with a WEE1.2 inhibitor. The use of claim 1, wherein the CHK1 inhibitor is selected from the group consisting of (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridine -3-yl) nicotinamide； (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3-yl) isobutyramide； (R ) -N- (5-bromo-4- (3- (methylamino) piperidin-1-yl) -1H-pyrrolo [2,3-b] pyridin-3-yl) nicotinamide； (R) -N- (4 - (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3-yl) -5-methylnicotinamide； (R) -N- (4- (3-aminopiperidin- 1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3-yl) cyclopropanecarboxamide； (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo- LH-pyrrolo [2,3-b] pyridin-3-yl) -3-methylbutanamide； and (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3-yl) -2 cyclopropylacetamide； in combination with a WEE1 inhibitor for the treatment of cancer. 3. The use of the composition according to claim 1, characterized in that the WEE1 inhibitor is MK-1775.4. The use of the composition according to claim 1, characterized in that the CHK1 inhibitor is (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3 -yl) nicotinamide. 5. The use of the composition according to claim 1, characterized in that the CHK1 inhibitor is (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3 -yl) isobutyramide. 6. The use of the composition according to claim 1, characterized in that the CHK1 inhibitor is (R) -N- (5-bromo-4- (3- (methylamino) piperidin-1-yl) -1H-pyrrolo [2,3-b] pyridin-3-yl) nicotinamide. 7. The use of the composition according to claim 1, characterized in that the CHK1 inhibitor is (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3 -yl) -5-methylnicotinamide. 8. The use of the composition according to claim 1, characterized in that the CHK1 inhibitor is (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3 -yl) cyclopropanecarbox
