Following a request of the European Commission, the European Food Safety Authority (EFSA) reviewed the scientific arguments raised by the non-governmental organisation Testbiotech requesting the review of Commission Implementing Decisions (EU) No 2021/66, 2021/61 and 2021/65 , authorising the placing on the market of products containing, consisting of or produced from the four-event stack soybean MON 87751 × MON 87701 × MON 87708 × MON 89788 (application EFSA-GMO-NL-2016-128), the five-event stack maize MON 87427 × MON 87460 × MON 89034 × MIR162 × NK603 and its subcombinations (application EFSA-GMO-NL-2016-134) and the four-event stack maize MON 87427 × MON 89034 × MIR162 × MON 87411 and its subcombinations (application EFSA- GMO-NL-2017-144). In relation to the four-event stack soybean and the five-event stack maize, Testbiotech argued that the risk assessment performed by the EFSA Scientific Panel on Genetically Modified Organisms (EFSA GMO Panel) is insufficient as regards molecular characterisation, comparative analyses, toxicological and allergenicity assessment and environmental assessment. For the four-event stack maize, Testbiotech claims that the risk assessment performed by the EFSA GMO Panel is inadequate considering the general knowledge gaps in the assessment of RNAi-based GM plants. EFSA's assessment focuses on scientific elements and does not cover legal aspects, as they are not in EFSA's remit and not in the frame of the mandate received from the EC. The assessment of the scientific arguments provided in the technical background of the three requests does not give enough justification to support the re-examination of the EFSA GMO Panel risk assessment conclusions and risk management recommendations.