In contrast, biopsy was not feasible for the RCC patients with ICI-induced SLR reported by Katagiri et al. and Purcell et al.; instead, a presumed diagnosis of SLR was made based on supportive clinical markers, such as elevated ACE levels, a temporal relationship with ICI treatment, and radiographic findings compatible with SLR [10,15]. Here, ACE is linked to renal cell carcinoma.