1475
When expressed in thymidine kinase - deficient L cells or 3T3 cells , C / EBPalpha is detected in a protein complex which binds to the E2F binding sites found in the promoters of the genes for E2F - 1 and dihydrofolate reductase ( DHFR ) .
 GENE: thymidine kinase; GENE: C / EBPalpha; GENE: E2F binding sites; GENE: E2F - 1; GENE: dihydrofolate reductase; GENE: DHFR
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: thymidine kinase; GENE: C / EBPalpha; GENE: E2F binding sites; GENE: E2F - 1; GENE: dihydrofolate reductase; GENE: DHFR