A method of evaluating the influence of perturbagens on skin homeostasis for cosmetic use, the method comprising: causing a computer processor to query a data architecture of stored skin instances with an unhealthy skin gene expression signature, wherein each skin instance is associated with a perturbagen and wherein the query comprises comparing the unhealthy skin gene expression signature to each stored skin instance and assigning a connectivity score to each instance, and wherein the unhealthy skin expression signature is constructed by a method comprising: (a) obtaining gene expression measurements for a plurality of skin conditions; (b) identifying genes differentially expressed in the skin conditions by comparing the gene expression measurements of (a) with gene expression measurements for a control sample; (c) causing a computer processor to calculate a gene expression consistency value by i) computing a log-odds ratios for the differentially expressed genes, ii) transforming the log-odds ratios using a sigmoid function, iii) performing a one-tailed t-test against zero, and iv) computing a log-odds ratio from the one-tailed t-test to achieve a gene expression consistency value; (d) creating an ordered list comprising identifiers representing the consistently differentially expressed genes, wherein the identifiers are ordered according to the gene expression consistency value computed in (c); and (e) storing the gene expression signature list on at least one computer readable medium; and identifying at least one perturbagen associated with an instance having a negative connectivity score that predicts that the identified at least one perturbagen will tend to reverse the condition associated with the unhealthy skin gene expression signature. (a) obtaining gene expression measurements for a plurality of skin conditions; (b) identifying genes differentially expressed in the skin conditions by comparing the gene expression measurements of (a) with gene expression measurements for a control sample; (c) causing a computer processor to calculate a gene expression consistency value by i) computing a log-odds ratios for the differentially expressed genes, ii) transforming the log-odds ratios using a sigmoid function, iii) performing a one-tailed t-test against zero, and iv) computing a log-odds ratio from the one-tailed t-test to achieve a gene expression consistency value; i) computing a log-odds ratios for the differentially expressed genes, ii) transforming the log-odds ratios using a sigmoid function, iii) performing a one-tailed t-test against zero, and iv) computing a log-odds ratio from the one-tailed t-test to achieve a gene expression consistency value; (d) creating an ordered list comprising identifiers representing the consistently differentially expressed genes, wherein the identifiers are ordered according to the gene expression consistency value computed in (c); and (e) storing the gene expression signature list on at least one computer readable medium; and identifying at least one perturbagen associated with an instance having a negative connectivity score that predicts that the identified at least one perturbagen will tend to reverse the condition associated with the unhealthy skin gene expression signature.