Specifically, we examined the expression of CD4, IL2RA, JAK3, STAT3, STAT5A, TOX, SELPLG, CCR4, CCR10 and CXCR3, and found that only STAT3 mRNA was expressed in levels that could be reliably detected by scRNAseq in the malignant T-cell clones of all MF samples. Here, JAK3 is linked to mycosis fungoides.