In summary, our studies have shown that the Trichoderma longibrachiatum strain (PKUT180420015) isolated from a biopsy specimen of a patient with pulmonary spindle cell carcinoma could induce atypical hyperplasia, with the expression of Ki67, CD3, CD56, GZMB, and PRF in mice, indicating that the fungus may be involved in inducing tumorigenesis. Here, MKI67 is linked to sarcomatoid carcinoma.