Propa.

Command your virus to invade cells, wage an all-out war against the immune system, and conquer the world.

Cell Battlefield

Cells are the primary battlegrounds of the game. You need to command your virus to enter host cells and utilize the replication mechanisms within the cell nucleus to rapidly reproduce. As the virus multiplies, the host cell's apoptosis signaling pathway will gradually be activated, eventually leading to programmed cell death. Sometimes, to achieve victory, you need to destroy all the cells; but at other times, you must ensure that a few cells survive to continue providing resources for viral replication.

Signaling Molecules

Once the battle begins, as your virus units increase in number, the host immune system will produce various signaling molecules with different functions to try to stop the spread of your virus:

• Apoptosis Inducers: Forcibly activate the host cell's apoptotic pathways to rapidly eliminate viral units that cannot escape in time.

• Target Host Cell Receptors: Bind to the spike protein receptors on the host cell surface, competitively blocking viral entry into the cell.

• Nucleoside Analogues: Act on the replication mechanism within the host cell nucleus, causing errors in the viral genome during replication and leading to the loss of critical genetic fragments.

• Budding Inhibitors: Prevent replicated viruses from leaving the host cell via budding, limiting further viral spread.

Surface Antigens

Surface antigens are specific molecular structures on the exterior of viral units, randomly composed of various colors and shapes. Each virus unit carries a unique set of four surface antigens. The host's white blood cells identify and engulf your viral units by recognizing these surface antigens. However, through viral mutation mechanisms, you can generate new surface antigens to evade immune recognition.

Controlling the types and quantities of surface antigens is sometimes crucial. When viruses with a specific set of surface antigens increase in number, the host immune system will gradually learn to recognize them, enhancing its immune response against the virus.

Genetic Fragments

Each virus unit can carry up to four genetic fragments, and the game provides multiple types of genetic fragments, each with its own unique function:

• Spike Protein Fragment: The most common genetic fragment, capable of unlocking the host cell membrane to allow viral entry for replication.

• Budding Protein Fragment: A key genetic fragment that allows the virus to leave the host cell after replication.

• Acceleration Fragment: Increases the speed of viral replication within the host cell, accelerating the spread of the virus.

• Blocker Fragment: Reduces the phagocytic capabilities of host white blood cells, enhancing viral survival.

• Mutation Fragment: Allows the virus to mutate into other genetic fragments with special abilities during replication, increasing diversity and adaptability.

• Hemorrhagic Fever Fragment: Directly damages the host's endothelial cells, leading to vascular wall damage and causing persistent bleeding.

• Signal Suppression Fragment: When deployed, suppresses immune signaling molecules in a certain range, preventing host cells from undergoing apoptosis or functional changes.

• Antigen Conversion Fragment: When deployed, erases all surface antigens of viruses within a certain range, making them unrecognizable and unengulfable by host white blood cells.

• Regulation Fragment: Repairs host cell surface structures exploited by the virus, delaying premature cell lysis and apoptosis to ensure a sustained environment for viral replication.

As the supreme commander of the viruses, you must constantly monitor environmental changes, adapt your strategies, and make full use of viral genetic fragments and surface antigens to engage in fierce battles with the host immune system. By continuously optimizing the virus's functions, you can achieve viral spread and evolution, ultimately conquering the entire world!