Adolescents and young adults face unique and often overlooked barriers to TB prevention and care. This case study highlights how the LIGHT research programme generated new evidence on the distinct challenges adolescents and young adults face across the TB care pathway in Malawi and Kenya. Using mixed-methods - including qualitative, quantitative, photovoice, and participatory workshops - LIGHT explored how gender, age, stigma, social norms, school, work, and economic pressures shape TB exposure, care-seeking, diagnosis, treatment completion and recovery. The case study demonstrates how LIGHT's evidence informed more youth-friendly and gender-responsive TB services, contributed to national policy and practice discussions, emphasised the importance of age- and sex-disaggregated data in TB programming, and positioned young people not simply as recipients of care, but as active contributors to designing better TB responses. Overall, it shows that designing TB services around the lived realities of young people, including men, can improve engagement with TB care and drive more equitable, people-centred TB care and strengthen the visibility of young people within the broader TB response.