cat trackDb.Glis3KO_kidneyP7.txt trackDb.Glis2KO_kidneyP30.txt trackDb.Glis2KO_kidney6m.txt trackDb.Glis2over_IMCD3.txt trackDb.Glis2over_IMCD3v2.txt trackDb.Glis3KO_Chitra.txt > trackDb.txt 
cat trackDb.Glis3KO_kidneyP7.txt trackDb.Glis2KO_kidney1w2w.txt trackDb.Glis2KO_kidneyP30.txt trackDb.Glis2KO_kidney6m.txt trackDb.Glis2over_IMCD3.txt trackDb.Glis2over_IMCD3v2.txt trackDb.Glis2KO71_IMCD3.txt trackDb.Glis3KO_Chitra.txt > trackDb.txt