Methods for treatment of cancer selected from lung cancer, ovarian cancer, squamous cell carcinoma, pancreas exocrine cancer, malignant melanoma, gastric cancer, esophageal cancer, a metastases thereof, and leukemia, in a human or non-human body, comprise administrating to the body a cancer-inhibiting amount of a first compound of Formula (I): or a physiologically acceptable salt thereof, wherein X, R1, R2, R3 and R4 are as defined herein.
