Reagents that regulate human receptor tyrosine kinase MerTK and reagents which bind to human receptor tyrosine kinase MerTK gene products can play a role in preventing, ameliorating, or correcting dysfunctions or diseases including, but not limited to, gastrointestinal and liver disorders, cancer, metabolic disorders (particularly diabetes), neurological disorders, cardiovascular disorders (particularly coronary heart disease), hematological disorders, reproductive disorders, endocrine and hormonal disorders, respiratory disorders (particularly COPD), and genitourinary disorders.