The paper presents the JWST/NIRCam transmission spectrum of the sub-Earth exoplanet GJ 341b, orbiting a nearby M1 star (d = 10.4 pc, K_mag = 5.6). The authors used three independent pipelines (Eureka!, Tiberius, and Tswift) to reduce the data from three JWST visits and performed various tests to check for the presence of an atmosphere. Overall, the analysis does not find evidence of an atmosphere. The null hypothesis tests show that none of the pipelines' transmission spectra can rule out a flat line, although there is weak evidence for Gaussian features in two spectra at 2.3 and 2.9 σ, respectively. However, these features occur at different wavelengths and are attributed to different gas species (CO_2 and O_3) in the two reductions, suggesting they are not real astrophysical signals. The forward model analysis rules out a low mean molecular weight atmosphere (< 350× solar metallicity) at 3σ and disfavors CH_4-dominated atmospheres at 1–3σ. The results are consistent with no atmosphere, a hazy atmosphere, or an atmosphere containing species without prominent molecular bands in the NIRCam/F444W bandpass, such as a water-dominated atmosphere. The study emphasizes the need for multiple reduction pipelines and rigorous statistical tests to robustly determine molecular detections in small exoplanet atmospheres.The paper presents the JWST/NIRCam transmission spectrum of the sub-Earth exoplanet GJ 341b, orbiting a nearby M1 star (d = 10.4 pc, K_mag = 5.6). The authors used three independent pipelines (Eureka!, Tiberius, and Tswift) to reduce the data from three JWST visits and performed various tests to check for the presence of an atmosphere. Overall, the analysis does not find evidence of an atmosphere. The null hypothesis tests show that none of the pipelines' transmission spectra can rule out a flat line, although there is weak evidence for Gaussian features in two spectra at 2.3 and 2.9 σ, respectively. However, these features occur at different wavelengths and are attributed to different gas species (CO_2 and O_3) in the two reductions, suggesting they are not real astrophysical signals. The forward model analysis rules out a low mean molecular weight atmosphere (< 350× solar metallicity) at 3σ and disfavors CH_4-dominated atmospheres at 1–3σ. The results are consistent with no atmosphere, a hazy atmosphere, or an atmosphere containing species without prominent molecular bands in the NIRCam/F444W bandpass, such as a water-dominated atmosphere. The study emphasizes the need for multiple reduction pipelines and rigorous statistical tests to robustly determine molecular detections in small exoplanet atmospheres.