Hyphal production is an important growth modification in yeasts and molds and illustrates the adaptive strategies of fungi to their environment. Yeasts, typically unicellular organisms, can develop hyphae or pseudohyphae in response to various environmental factors, including temperature fluctuations, nutrient deficiencies, or interactions with host organisms. A prime example is Candida albicans. It can produce both true hyphae and pseudohyphae mitotically without sexual reproduction in response to various environmental factors. Asexual reproduction (mitosis) is sufficient to produce these hyphae forms. Pseudohyphae cells are generally ellipsoidal (i.e. their width is greater in the middle than at the ends) and have constrictions at the septal junctions. In contrast, hyphal cells usually have parallel sides, are uniformly wide, and have septa without constrictions (Lu et al, Trends Microbiol 22(12):707–714 2007). On the other hand, Cryptococcus neoformans usually reproduces mitotically in the unicellular yeast form by budding. Under conditions that trigger sexual reproduction, such as dehydration/desiccation or nitrogen starvation, the fungus (cells of the opposite mating type α and a) undergoes the morphological transition from yeast to hyphae. Hyphal formation enables the uptake of nutrients from the environment and the production of stress-tolerant infectious spores (Chen et al, Virulence 11(1):337–348 2020). Since the transition from yeast to hyphae in Cryptococcus is clearly and closely linked to its sexual reproduction, it was not considered a classical dimorphic pathogen. This morphological change increases its virulence and its ability to invade host tissues, contributing to its role as an opportunistic pathogen. The ability of yeasts to switch between unicellular and filamentous forms emphasizes their remarkable plasticity and adaptability in different environments. In contrast, molds such as Fusarium sp. and Aspergillus sp. naturally exist in a multicellular, filamentous form consisting of hyphae. This structure is crucial for nutrient uptake, as it allows molds to efficiently absorb organic matter from their environment and facilitate reproduction through sporulation. Unlike yeasts, hyphal growth in molds is not dependent on specific environmental triggers, but is a continuous and integral part of their life cycle. This distinction emphasizes the diverse growth patterns within the fungal kingdom, with hyphal formation fulfilling different functional roles depending on the organism. Understanding these growth dynamics is critical for both ecological studies and clinical applications, as the transition to hyphal growth in yeasts can significantly influence pathogenicity. Furthermore, this knowledge can inform strategies for the treatment of fungal infections and the development of antifungal therapies. Ultimately, the study of hyphal production not only reveals the complexity of fungal biology but also highlights the evolutionary adaptations that allow fungi to thrive in different niches (Chow et al, Pathogens 10:859, 2021; McGinnis, Tyring, Introduction to mycology. In: Baron S (ed) Medical microbiology. University of Texas Medical Branch at Galveston, Galveston, 1996).