The information regarding the SP-D mRNA expression in breast cancer was obtained from Zhao’s, TCGA’s, and Curtis’s datasets, which showed that SFTPD was expressed at a lower level in invasive ductal breast carcinoma, male breast carcinoma, and breast phyllodes tumor, compared to normal breast tissues (Figure 4A, p < 0.05; Figure S3A in Supplementary Material, p < 0.05). Here, SFTPD is linked to breast cancer.