Overall, there is sufficient published data to suggest that NO may be an important regulator of palmitoylation dynamics. The development of more sensitive techniques to directly study nitrosylation is required to more rigorously delineate interplay between this modification and palmitoylation. It will be particularly important in future studies to determine how palmitoylation dynamics are affected by endogenously produced NO. The intracellular diffusion range of NO from its site of production is limited, and thus, interplay between palmitoylation and nitrosylation The impact of sex, gender and pregnancy on 2009 H1N1 disease Children and young adults of reproductive age have emerged as groups that are highly vulnerable to the current 2009 H1N1 pandemic. The sex of an individual is a fundamental factor that can influence exposure, susceptibility and immune responses to influenza. Worldwide, the incidence, disease burden, morbidity and mortality rates following exposure to the 2009 H1N1 influenza virus differ between males and females and are often age-dependent. Pregnancy and differences in the presentation of various risk factors contribute to the worse outcome of infection in women. Vaccination and antiviral treatment efficacy also vary in a sex-dependent manner. Finally, sex-specific genetic and hormonal differences may contribute to the severity of influenza and the clearance of viral infection. The contribution of sex and gender to influenza can only be determined by a greater consideration of these factors in clinical and epidemiological studies and increased research into the biological basis underlying these differences. Sex and gender differences can affect exposure to pathogens, vulnerability to infectious diseases, health seeking behaviours and immune responses to pathogens, resulting in differences between males and females in the incidence, duration, severity and case fatality rates following an infection [1, 2] . Sex refers to the biological and physiological characteristics that define males and females, whereas gender refers to the roles, behaviours, activities and attributes that individual societies consider appropriate for men and women. The impact of sex and gender on infection is tied to the age of the individual, as both biological and cultural factors can change dramatically with age. Consideration of these factors can result in a more effective public health response to infectious diseases, including influenza, and yet they are often inadequately addressed in clinical and basic research studies. A systematic review of the literature regarding sex, gender, pregnancy and the 2009 H1N1 pandemic indicates these are important factors which alter the severity of the disease as well as the prevention and treatment measures. A greater awareness of how sex and gender impact upon the biology of 2009 H1N1 infection could provide important insights into the unique morbidity and mortality patterns associated with this pandemic.