An application was submitted by Bayer CropScience AG to request the authorisation of genetically modified cotton stack GHB614 x LLCotton25 (tolerant to glufosinate ammonium and glyphosate-containing herbicides) and all sub-combinations of the individual events as present in the segregating progeny, for food and feed uses, and import and processing, in accordance with articles 5 and 17 of Regulation (EC) N? 1829/2003 GM Food and GM Feed. The unique identifier assigned to GHB614 x LLCotton25 cotton is BCS-GH??2-5xACS-GH??1-3. The genetically modified cotton stack GHB614 x LLCotton25 has been obtained by conventional crossing of two genetically modified cotton events: GHB614 and LLCotton25, without any new genetic modification. The EU-RL GMFF has previously validated individually, and declared fit for purpose, the detection methods for the single events GHB614 and LLCotton25 (see http://gmo-crl.jrc.ec.europa.eu/StatusOfDossiers.aspx). In line with the approach defined by the ENGL (http://gmo-crl.jrc.ec.europa.eu/doc/Min_ Perf_Requirements_Analytical_methods.pdf) the EU-RL GMFF has carried out only an in-house verification of the performance of each validated method when applied to DNA extracted from GHB614 x LLCotton25. The herewith reported in-house verification study lead to the conclusion that the individual methods meet the ENGL performance criteria also when applied to DNA extracted from the GM cotton stack GHB614 x LLCotton25.