Table 1.

Several major findings related to methodologies used in research on humans.

Key Findings	Major Methodologies
A role of skin TRM in protective immunity in humans	FACS	[58]
Skin TRM with the potential of producing cytokines are infiltrated in the lesion of patients with GVHD	FC, single-cell TCR sequencing, and IF	[46]
Cells residing in nonlesional skin are sufficient, and the recruitment of circulating cells is not necessary for the development of psoriatic disease	Transplantation, FC, quantitative RT-PCR, and IHC	[76]
CD8+ TRM producing IL-17A in the epidermis is one of the characteristics in psoriasis	FC and IHC	[87]
The increase in IL-17A-producing CD8+ TRM during the distribution of IFN-γ-producing TRM occurs according to psoriasis duration	FC and IF	[88]
The successful treatment with IL-17A-targeting biologics results in a decreased number of IL-17A-producing CD8+ TRM in resolved psoriatic skin, but the frequency of these cells is not altered	FC, IHC, and IF	[91]
IL-17A-producing CD8+ TRM and IL-22-producing CD4+ TRM remain in the psoriatic epidermis for as long as six years after starting the successful TNF-α-targeting treatment	FC, quantitative RT-PCR, and IF	[62]

FC: flow cytometry, TCR: T-cell receptor, RT-PCR: reverse transcription polymerase chain reaction, IF: immunofluorescence, IHC: immunohistochemistry.