**4. Conclusions**

Fungal–metal interactions such as the synthesis of nanoparticles and metal used as antifungal agents are on the rise. Studies on metal toxicity and resistance have uncovered preserved homeostatic mechanisms. This review discussed metal homeostasis in various fungi types and has shown that essential metals have designated uptake and transport systems that regulate metal ion balance, mostly through the model organism *S. cerevisiae*. However, there was a significant lack of fundamental knowledge of such mechanisms in filamentous fungi, which play critical roles in nanoparticle biosynthesis and are targets of metal antifungals, further accentuating the need to investigate molecular systems involved in metal homeostasis. Fungal homeostasis of the non-essential metal silver was also highlighted. It showed that homeostatic mechanisms were reliant on existing copper transport systems, but were largely unclear regarding overall cellular processing. There is a need to further investigate other non-essential metals' cellular homeostasis as their commercial usage increases, due to the current lack of knowledge of future implications.

**Author Contributions:** J.R.R.; O.S.I.; F.N.A.; all authors contributed equally to this publication. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by a Title III HBGI Grant sponsored by The US Department of Education.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data sharing not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

