Gal-3 inhibition significantly attenuated cardiac injury (injury score: 0.00 ± 0.00 vs. 7.17 ± 0.75 in severe IH; <i>p</i> < 0.001, η<sup>2</sup> = 0.859).<h4>Conclusions</h4>SP-D demonstrates severity-associated alterations consistent with alveolar epithelial stress during IH, though high variability limits definitive biomarker validation in this sample. Here, LGALS3 is linked to isolated hemihyperplasia.