Further analysis confirmed that within the MM_Immune subgroup, the proportion of PD-L1-positive cells in tumor cells was the lowest, potentially due to the influence of FOXD3 (Figure S4E). However, it is important to note that the proportion of PD-L1-positive cells is lower in the PD-pre group compared to the NPD-pre group, which may provide an explanation for the fact that the expression level of PD-L1 is not the sole determinant of anti-PD-1 therapy efficacy. Here, PDCD1 is linked to neoplasm.