**8. Conclusion**

When we put all these data and review together, we attain at a consistent outline for the action of keratins, growth factors and cytokines in psoriasis. MTX has been used as a effective agent in the treatment of psoriasis from the decades of 1960s. But still its mechanisms of clearing psoriatic remains ill-defined. In conclusion, we strongly thought that MTX inhibits the hyperproliferation of KCs by decreasing the levels of IL-1 and caspases-1 (activating signals), TNF-α, IFN-γ and by increasing deactivation signal through various effective pathway. Also it efficiently regulate abnormal keratins by upregulating K10 and downregulating K14, K16 and K17, thereby maintaining the normal phenotype in KC (**Figure 7**). Mutation in keratins filaments were also observed in psoriasis [31]. Thereby, understanding keratin functions and related regulatory mechanisms will help to design new therapeutic interventions for keratin-related skin diseases. We strongly concluded that MTX roles on controlling the KC-immunocyte cycle by activating important keratins and deactivating abnormal kertains showed its well-organized therapeutic effect in psoriasis patients.

### **Figure 7.**

*Effect of MTX on KC activation cycle. MTX normalizing or reversing the phenotype of psoriatic KC but altering the inflammatory mediators as well as keratin proteins in KCs. Symbol ↑ indicates increase in psoriasis; symbol ↓ indicates decrease in psoriasis.*
