question: What is the yeast ortholog that has a subpathway of GGR and GeneCards entry CETN2?
answer: SELECT yeast_ortholog FROM table_name_19 WHERE subpathway = "ggr" AND genecards_entry = "cetn2"
context: CREATE TABLE table_name_19 (yeast_ortholog VARCHAR, subpathway VARCHAR, genecards_entry VARCHAR)