Study	Purpose	Sample size	Outcome measures	Relevant Findings
Flohret al.[@308379]	Correlation between FLG mutations and skin barrier functions in humans with or without eczema	88 infants below age 3 months	SCORAD eczema severity scale, TEWL measurement from forearm, venous blood samples to identify FLG mutations	High median of TEWL measurements in children with FLG mutation carriers even if child did not acquire eczema compared to wild type infants. Positive correlation between FLG mutation carriers and diagnosis of eczema by the age of 3 months. Skin barrier impairment precedes eczema instead of being a characteristic of skin condition.
Zhang et al.[@308377]	Explore genetics behind skin barrier functions and TEWL	611 healthy skin samples	Determining P values statistically significant correlation (p<0.05)	P value of 3. 11 x 10^-8 significant correlation between TEWL and genetic marker 9q34.3 variant. Ancestral gene (G) is which carries the 9q34.3 variant reduced TEWL by almost 19% therefore increasing barrier function.
Park et al.[@308380]	Investigate association of compound K	Six-week- old female hairless mice skin	SPINK5 mRNA expression levels in CK	CK regulates SPINK5 expression.
	and SPINK5 in regard to barrier function		compared to the TEWL levels and skin health	CK can enhance skin barrier function that is weakened by UVB. Upregulating SPINK5 expression regulated TEWL to a healthy level.
Oh et al.[@308381]	Understand role of ALCAM on atopic dermatitis	44 healthy controls, and all children treated for atopic dermatitis	ALCAM serum levels, flow cytometry rate to measure lymph nodes drainage, statistical analysis of results (p<0.05)	ALCAM negatively affects skin barrier health and TEWL. ALCAM increases T-helper 2 cell production in AD patients to aggravate = symptoms.
Taïeb A. (2018).	Review molecular and cellular changes during neonates that help shape TEWL	Compiled data from 21 studies.	Used measured TEWL data from previous studies on neonatal infants for several weeks postnatal	Neonates had an increased amount of aquaporin and tight junction dependence which decreased as skin matured and TEWL levels started to decrease several weeks after birth.